The following are riding impressions of scooters I have owned

Honda PA 50 Moped

The very first scooter-like bike I got was a Honda PA 50 back in 1996. I had been buying and selling bikes for a few years, and I got it in trade along with 2 other motorcycles. It needed a seat cover and some TLC. Once I got it running I putted around the neighborhood. My first impressions of riding a moped was how light it was, and how slow it was... But it was fun. It felt more like a bicycle than a motorcycle, with the open frame and handlebar/seat layout. I could raise the seat just like a bicycle. On flat ground, it would do 25 mph. I rode it in the bicycle lane - it was not safe to ride it on the road because it accelerated too slow and the top speed was limited. It would not climb hills worth beans. I could bicycle up most hills faster than riding this moped. You'd have to use the pedals to maintain 5-10 mph if the hill was steep enough. But it was fine on flat ground.  I had to mix the gas and oil - a pain, but not too difficult.

Yamaha Razz

This was my first real scooter.  It was quite a step up from my Honda moped.  Cute and lightweight, it was red in color and only has 298 miles on it when I got it.  Firstly, I had to get used to starting it.  I've owned dirt bikes (and street bikes) for years, so my first inclination was to kick start it because it had a kickstarter.  After a quick tuneup, I was able to get it started easily in 2-3 kicks.  What a blast to ride!  The acceleration was way better than my moped.  It had a two speed automatic transmission, which allowed it to climb hills much better than the moped.  Top speed was an indicated 27 mph.  Once a got a new battery, I tried the electric starter but it wouldn't work.  I disassembled the front fairing pieces so I could trace the wires.  Lo and behold, there were wires running to the brakes that had to be connected in order for the scoot to run.  You connected them by putting on either brake.  Welcome to the world of scooters!  This was a safety device to prevent you from taking off (remember no transmission) when you first started the bike.  I didn't know that almost all Japanese scooters had this safety feature.

Yamaha Jog

The Jog is a similar size to the Yamaha Razz, but it's quite a bit faster.  It will do ~40 mph compared to 25-28 mph with the Razz.  The brakes/suspension, and some of the components are better quality.  They share a ver similar engine, but the Jog has a slightly bigger carb and maybe some other performance mods.  Anyway, it was great to have the higher top end.  I would still ride the Jog in the bicycle lane, but when I got above 25 mph I'd try and creep into the right hand lane of traffic.

Honda Spree

This scoot was very similar to the Razz in terms of acceleration and performance in general.  Of course the styling is different.

Honda Elite 80

This scooter was a bit of a disappointment.  I figured that because it was 80cc instead of 50cc, it would be faster than the 50's.  Not necessarily true.  The four stroke engine felt sluggish compared to the two stoke engines in the 50cc scooters.  Top speed was fair - about 42 mph.  Top speed among these models varies a bit, but you will not get much over 45 mph with a stock scooter.  At least I didn't have to worry about mixing oil/gas or adding oil to the injector tank like on the 50cc two strokes.

Yamaha Riva 125

This scooter has good performance up to about 40 mph, then it will slowly continue to pull until maybe 50-55 mph.  I was impressed with the acceleration up to 40 mph - it would accelerate as well as the Riva 180.

Honda Elite 150

I traded my Honda PA50 moped plus some cash for my first Elite 150.  After riding this moped and some other 50cc scoots, I was amazed how fast the 150 was!  Finally, I didn't have to be embarrassed about being on the road.  The first time I rode it, what fun it was to watch the speedo go from 25 to 35 to 45+.  I couldn't wait to do the trade.  I rode around on it for a while, and then late one night I decided to take it on the freeway.  This is when the max speed limit was 55 mph.  It was a little scary riding a scooter on the freeway for the first time.  (Not I was not a novice rider at this time.  I'd been riding dirt/street bikes for 25 years).  The light weight of the scooter, plus the small wheels made it feel a little unstable.  The 150 tops out at 60-65 mph, so maintaining 55 mph was not a problem.  But at any slight upgrade, I'd loose maybe 5 or more mph.  This is really a freeway scooter.  (Note that in California, 150cc is the minimum you need to ride on the freeway).  These days, with the 65 mph speed limit (and traffic traveling 70+ mph), I would not take the 150 on any of these freeways.  But it would haul two people around easily most anywhere else.

Yamaha Riva 180 and Riva 200

These big Rivas are very versatile!  In general, the bigger sized scooter you get, the more you can do with it.  You can easily keep up with traffic, climb hills, and haul a passenger & climb hills at the same time.  I sell quite a few scoots to people in San Francisco.  These big Rivas (and the Honda 250's) are the only scooters that can go anywhere and haul another person, without apology.  My Riva 180's would do 65-70 mph, and my 200 would do an indicated 72 mph.  This is generally fast enough for the 65 mph freeways, but it doesn't leave you a lot of breathing room.  These Rivas work great on the 55 mph freeways - they'll go all day at 55-60 mph.

Honda Elite 250

All I can say is - wow what a scoot!  In some ways, the Elite 250 feels more like a motorcycle than a scooter.  At idle, it sounds and feels like a motorcycle.  It actually vibrates a bit just like a motorcycle.  Acceleration is not blazing, but you can leave a *lot* of cars in the dust.  It will easily haul two people around.  It will cruise all day at 65 mph.  My top speed for an Elite 250 is ~75 mph.  The bigger scooters like the Elite 250, Riva 180, and maybe the Elite 150 are heavier, taller and wider than the small scooters (naturally).  They are more stable at higher speeds, but they're still not as stable as a motorcycle.  This is mostly because of the small wheels and short wheelbase as compared to a motorcycle.

Honda Helix

Lastly, for me, is the Helix.  When these scooters (I guess you can properly call them scooters) first came out in 1986, I thought they were really ugly.  I still don't find them very attractive.  But they are very well designed and quite functional.  The 2.3 gallon gas tank is large by scooter standards, so you don't have to fill up every ~70 miles.  Wind/rain protection is very good.  The rear trunk is pretty large, and it allows you to keep your stuff hidden out of sight as compared to using a wire basket.  The wheelbase is very long.  At first this is disconcerting.  Slow speed handling is funky until you get used to it.  Side winds affect this scooter much more than other scooters because of its large size and long wheelbase.  But, the Helix is very stable at highway speeds.  It likes to eat up miles on the freeway.  Acceleration is very good from the 250cc engine, and I have seen top speeds of 77-79 mph.

Late breaking news - the previous Helix I owned was about 4 years ago when the speed limit here in California was 55 mph. The Helix was great on the highway at 60-65 mph (the speed most of the traffic was going. However, I recently owned and drove another Helix. Now the speed limit is 65 mph, and traffic routinely goes 75 mph. The Helix just cannot keep up at these speeds. For short jaunts (~10 miles) it's ok, but I'd really like to have +10 mph more available. The new Reflex 250 is supposed to do 80 mph. I'd love to try one of these scooters out and see how well it does.

Honda Reflex

Yamaha Majesty

Honda Silverwing