My band is just making the switch to IEM's after decades of live playing via Conventional means. (amps onstage, acoustic drums, vocal wedges etc.) I've purchased a set of Shure SE315 (about $200.00). They sound very good. I A/B them with my studio headphones and they are very close. They are a single driver and so they might not work well for a drummer or Bass player desiring a heavier bottom end that comes when using dual or triple drivers, but for me...It's like listening to a CD...(I don't like an over ephmasis on the bottom anyways...I like what goes in to come out..an accurate representation. These Shure units do that).
We each have a small Netbook at our mic positions and it enables us to have control of our own monitor mixes. Our drummer is playing a dampened Acoustic kit with custom built triggers / sensors into a Yamaha drum brain. I'm using an XTLive and an HD500 (I'm transitioning sounds at the moment....). Bass player goes DI and is using a bass amp SIM in the mixer.
I should mention that we can do a lot of this due to the fact that our FOH Mixer is a digital mixining system from RML Labs called SAC (Software Audio Console). One of the best digital mixers I've used and that includes many dedicated hardware consoles.
Withour drummer playing a triggered kit we've had a very low stage volume so the transition to IEM's and running my POD's direct to house (No stage amps..)....our sound tech will have total control of our sound as there will be no stage bleed.
I'd say go for it but you've got to maintain the ability to control your onstage mix and that's where things can get expensive. However, with SAC, each monitoring station cost me $80.00 as I am using some 2nd hand Netbooks... A considerable savings over the Aviom or even the Behringer monitor control systems. With SAC we can run the Remote's wireless or Wired via CAT5 cable. FOH is wired via digital snake as well so there's no losses. (ADAT extenders from Appsys )