I'd be interested in the antenna performance as well, I am one of the "few" who have the antenna issue on my Iphone 4, since I use it without a case I tend to bridge the line often and with low reception at work as is, I drop a lot of calls.
This would be the one reason why I'd consider upgrading to the 4s but I'd like to be sure this is no longer an issue. Anyone who had issues with their 4 if they can compare with their 4s would be great!