I beta-tested the app and bought it almost as soon as the buy link was available. It worked great for me under Query Analyzer, SSMS beta and SSMS release. I don't use VS much for SQL, so can't really comment on that. I did notice the SQL Login prompt a couple of times, but mostly if I had network trouble (or in one instance had to alias my machine).
The programmer was always very quick to respond to my suggestions and requests for help. I'd recommend contacting him with details of your problem if you're having trouble. Be sure to capture a log first - that's not enabled by default.
Atadore's running a list of suggestions/bug fixes on his site as well. You can suggest new features or check on the status of existing requests to see if they will be in the next version. He's implemented several of the ideas already. I also find it cool that he's not a SQL Server guy. He's a programmer who saw this opportunity and developed the idea.
Only change I'm waiting for now is a minor tweak that will display columns when you expand something in the actual column order. Atadore has a minor bug in 1.2 that sorts columns treating the order as a character instead of an int. He wrote back and explained that it was missed in testing, but fixed for the next release.
For the $25 this cost, it was well worth it. Here's hoping that he doesn't get snatched up by some large company that will boost the license cost through the roof. :-)