Game runs smoother when profiling on an iPad 2/iPhone 4s, sluggish otherwise

We have a puzzling issue where our game (an endless runner/side scroller) appears to run smoother when the profiler is attached to our iPad 2/iPhone 4s (our minspec devices). We have had numerous eyes look at the game and confirm the same thing. Release builds also appear to run sluggish compared to development+profiled builds. We're using Unity 4.6.6p3.

Here's the repro: Make development build, don't debug with xcode Start up game and attach profiler to the iPad 2 Game runs fine with no major hitches/maintains steady 33ms frametime, our in game FPS counter also shows 30FPS Unplug the iPad and the game will continue to run fine Next, close the game and start it up again. The game will appear to run sluggish despite our in game FPS counter still showing a steady 30FPS.

This is very strange behavior and quite difficult to debug. It doesn't show up on an iPhone 5 that we've tested with. I thought it might be vsync related, but I don't know how the profiler would affect our quality settings (Vsync on, Every V Blank) and from what I understand iOS forces vsync on anyways. I found a couple other mentions of this happening to other people but on Android (one, two). Does anyone know what special sauce the profiler is cooking up to cause this discrepancy? Any ideas or help would be greatly appreciated!