I had a 7210 (basically the 7250 but the camera was an external attachment rather than built-in) before switching to the 3650 and couldn't sync. Maybe there's an app, or I guess you could run VPC and use the Nokia Suite though I'm not sure how well that would sync.
The 3650 is a unique shape, but it is bluetooth-enabled and I've had no problems whatsoever syncing with my Mac nor my pda (Tungsten T has built-in bluetooth). The camera features work better, there's more apps and the external memory cards are great. I've only seen the 7250 from a few friends and it seems solid enough, but it doesn't have half of what the 3650 have. After about 2 1/2 days of learning the keypad for quick sms, I didn't miss the 7210 one bit.