DougL wrote:Burgman 400 handles like shit (not my opinion, but from a friend who has owned every maxi under the sun) and the Piaggio 400cc engines and above are agricultural. If you want the smoothness of your GTS you'd be better with the Beverly 350 or X10.

Bevely 350,and x10 are way out of my budget ive not considered them

Can't speak for the Suzuki....but the Xevo was a great machine (practical/roomy/fun/powerful/economical).
Only changed to the X10 (better machine) because (at the time) I could afford to.

Asking for opinions between bikes is like talking politics. Burgman owner are often extremely biased towards their bikes and rightly so as they are good, but any Italian bike owner will tell you...boring!
I don't think the newer Piaggios are as well built as the older stuff, nor are the electrics any better or more reliable, but they still have character which compensates for any foibles they may have.
The only was to decide is for yourself as every bike is different. You may end up with the most perfect Piaggio ever made or the worst Burgman ever, and the only way you will decide is to go look at them. The above posts cover the basic differences for comparison, the rest is personal preference.
Good luck with the Piaggio which you should buy, as you will know it's the best when you try it.