i've used IEMs to track in live rooms with a really loud amp going. its mainly a personal preference thing for me, plus i get better isolation with my IEMs for tracking.
Have used Westone UM-1 and Shure E2C, find the UM-1's flat response much better suited to critical monitoring applications. but if you have the cash, suggest that you try dual-driver IEMs ilke the UM-2 for a more enjoyable monitoring experience. You can check out the Jays IEMs as well, the D-Jays (single driver) and Q Jays (dual driver). They're in the same price range as the similarly spec'd westone IEMs and sound quite decent. Another option is the Klipsch Custom 1, which i'm told is a pretty decent single-driver IEM.