I have a iPhone5 and DroidX, both 4" displays... I like it better without the mobile theme. It used to default to the mobile theme, since I changed it visitors from mobile devices are actually way up.
... I'm starting to shy away from doing multiple layouts because I feel that people will be using their devices browsers much like desktop browsers. You might not be doing that now, but I bet you will. It saves me time that I can put towards other efforts.
What I could do, and I think this would make everyone happy, is add a notice for mobile detected users. Nonintrusive, but visible on the page unless hidden. Asking if you'd like to simplify the layout.
Thanks, I use the site often on my iPad so I try to make it work right with it. It has a little different feel than a desktop, it definitely processes information differently... you can see by how the progress bar loads. Before I got my iPad I was using Xcode to emulate it... I think it's awesome that the emulator feels exactly how the real iPad does. Really helped me develop for it when I didn't have one.
I've noticed that the iPad definitely has its speed limitations... no matter how fast the connection you're on. Maybe software limited... I have a Retina iPad (my iPad Speed Test Results). Best I've seen is ~ 43Mbps / 5Mbps but only an average of 18.8 Mbps / 3.7 Mbps... on a 150/20 Mbps connection. Granted, the best I've seen on this supposed 150 Mbps / 20 Mbps connection is 95/15 --- but even at that speed it's obvious that the iPad isn't going to go faster, it has more than enough on tap if it were able to. I bet with some software modification it could go faster.....