Android phone responsiveness varies by a huge amount. Some are lightning fast while others just have lots of lag throughout the ui. I have found lg phones to be in the latter category.

Maybe it's the version of Android? I just got the HTC One X and everything flies on that phone. No delays or lag on anything. Best phone I've used to date (and I've had all iPhones except the 4s).

That's because in iOS the UI has maximum priority. It can even pause the app so the UI keeps a high framerate.

That's pretty odd since I have a HTC Desire (single core 1GHz) which works really well. (Never been an iPhone owner though)

See if something like a 3rd party ROM like cyanogenmod is supported on your phone or just return it and get something like one of the HTCs or better yet an unlocked Galaxy Nexus straight from Google.

Pre-ICS versions of Android kind of sucked, due to the lack of GPU acceleration.

I suggest you look for a CM9 ROM for your phone on XDA.