It all depends on your source. You would be most likely to tell the difference if your source was Blu Ray. Most HD TV is 720p or 1080i which would be difficult to tell the difference between.
IMO, you have your TVs backwards. You would have been better off with 1080p in the larger screen (42 inch) and 720p in the smaller screen (32 inch).
The smaller the screen, the more difficult it is to tell the difference of 1080p vs. 720p