The reports from RootzWiki forums have said that there can be inconsistent behavior when using the phone in landscape mode. Some users found that while playing games in landscape mode, the bottom right corner of the screen would eventually become unresponsive. Of course, there is a super easy fix, which is simply to turn off the screen and turn it back on. Still, it's an issue that could definitely cause some annoyance. Although, we'd definitely say that this is not nearly as annoying as how long it takes the phone to reorient from portrait to landscape.
No word on any possible fix from Google on this one, but as you can see below, the issue has been reproduced on both GSM and LTE models of the Galaxy Nexus.