First of all, it's a scooter....rather, a maxi-scooter...designated by having over 250cc's. For everyone who say's '...it's really just a motorcycle without gears...' well, they would be wrong. Although it does share many characteristics of a traditional motorcycle, it is very, and remarkably, different.
Zipping around town is a blast and effective. It is, buy far, the most utility-featured two-wheeled vehicle out there in my opinion. The large under-seat trunk can fit two, full-size helmets - which translates into four good sized grocery bags if needed.
But, this is a long-distance touring blog, so I shall restrict my comments to that end. In that mode, it has served me well. Since I wrote extensively about the positive and negative features of this scooter in the rolling blog pursuant to my long trip, I won't repeat myself here.
But I do want to add two significant points. Size of the rider. I am 6'3" and weight 230. With my gear and me, I pretty much max out the payload capacity of the scooter. Worse though, the scooter is just not really built for guys my size. I mean, I could - and did - manage, but it is not the ideal vehicle to maximize the comfort of those over 6' in my opinion.
The Burgman 650 does have room for multi-positioning of your feet since there are running boards instead of foot pegs. With me though, the downside was my knees. I had to be very conscious of where my knees were at all times. They just tended to rest lightly against the lower dash - which was fine 90% of the time. I would just slightly adjust them when I anticipated bumps and all would be fine. It's those bumps, holes, etc. that I didn't anticipate that drove the dash into my knees with throbbing regularity.
A sub-point to that is the lack of suspension. It has adjustable rear shocks, but I could never find the magic number that dampened the ride to the level of actually being comfortable. Meaning, it retained pretty much the sports aspect of suspension - which suits the scooter fine in everday driving, but quickly tires the rider out on long trips. So, in one hand, you have a good read/feel of the road when you need it.....and even more so when you don't need or want it. No choice.
The second point is reliability....and this may strike some as odd. I say that because my B650 performed flawlessly for the 3 years I owned it. I did my own service on it (except for tires) and it never failed me. Ever.
That said, I belonged and socialized with many scooter enthusiasts and frequented rallies, forums and websites. From those sources, I came to learn that there really wasn't a long history for which to make reasonable calculations about the service length of the vehicle - which was unsettling for me.
I couldn't find a source on the web that boasted mileage over, say 60k. I am sure they are some out there, I just didn't see much legacy to that end. Conversely, I did know of, and read, much about CVT failures. They are incredibly complicated devices and when they go, unless you have a new scooter, you find yourself with a bill equal to or greater than the actual value of the bike!
That aggregate concern over long-term/high-mileage B650's is one reason why I was keen to give it up. If I had my druthers, and if I still wanted to have a B650, I would get another used on, under 10k miles, and sell it before I hit 30k miles or so.
No real reason except for peace of mind.