I used VS.PHP for quite a long time.
What I liked in VS.PHP is Microsoft GUI (used to work in ms studio since fabulous v6.0), it's fast and highly customiziable. What I disliked in VS.PHP is xdebug debugger. You never know what statement in watch will terminate debugging. It always happen all of sudden. You step, step, step, then it just stops. Removing watches solves the problem completely, but it's not a good solution I'd recommend to anybody.
I didn't encounter any problems like this in DBG debugger -- they provide both. Unfortunately they don't update dbg for years and it does not support php 5.3. Last version seems to be 5.0.4 which is outdated now. That's why I switched to PHPEd (www.nusphere.com)
Hope it helps, and perhaps it explains why nobody else replied to your question (at least that's my 2c)
-jv