Well, I can speak for both. I had a 2000 Vstar 650 that I bought new and sold last year and I just bought an M50 a couple of months ago. Here's my thought on each:
Vstar:
Beautiful bike; Harley Fat-boy clone. I was told constantly what a nice Harley it was.
VERY comfortable seat and riding position.
VERY "buzzy" at higher speeds (55mph+). Really needs a 6th gear.
Not very quick off the line. Just too small of an engine. Don't expect to keep up with others on larger bikes.
VERY low center of gravity which makes the bike feel very stable but also VERY easy to drag the pegs and pipes in the corners.
Too small of an engine and too soft of suspension to ride comfortably when riding with an adult passenger.
Very reliable. I had NO problems of ANY sort with the bike in almost 5 years of ownership.
Has auto-cancelling turn signals which I really miss on the M50. Such a simple feature that is very aggravating not to have.
On the other hand, the Vstar has NO fuel guage or low fuel warning. The M50 has a low fuel light. The Vstar has a reserve tank. When the engine started to sputter, I just reached down and moved the lever to reserve.
M50:
I haven't had it long enough to comment on the reliability.
VERY sharp bike. Hard to be mistaken for a Harley even though a couple of people have asked me what kind of Harley it is.
I really like the lack of chrome but I have found that the black wheels show dirt VERY well. Much more so than chrome but the mag wheels are easier to clean than wire spoke.
The M50 is MUCH quicker off the line than the Vstar and pulls hills much better.
The M50 is a little "buzzy" at high speeds too but no where near as much as the Vstar was.
I LOVE, repeat LOVE, the fuel injection on the M50. Starts right up in the morning. No waiting on the choke. No backfiring while cold. Quick acceleration and throttle response.
I love the water cooling on the M50 however I have noticed that in really hot weather, while sitting at a traffic light that the electric fan on the radiator kicks on and literally blows hot air right onto the inside of my legs. This is more of a nuisance than an issue but it would have been nice if Suzuki had made some type of air deflector behind the radiator. I'd still rather have water cooling though. A cooler engine is better for longevity and dependability.
Now to my BIGGEST complaint on the M50: THE SEAT SUX!! Even though I've already done the "seat mod", I can still feel the bracket hitting my tailbone. Suzuki has already received a nice two page letter from me expressing my disappointment in this. Apparently this problem generally only affects larger riders such as myself (6'-240lbs) who ride far back on the seat.
My M50 is actually for sale right now (check the classifieds) and the seat is one reason why.
Between the two bikes though, I would still choose the M50 if it wasn't for the seat. The Fuel Injection, looks, and performance are far superior to the Vstar IMO. See if you can come up with a way to ride an M50 for a while before you buy to see if the seat is an issue to you. If you're a smaller or average size person, I suspect that you won't have any issues with it.
Sorry for the long post, but thought I would give you as much info as possible to help make your decision.
let us know what you end up with!
Drag