4-piece band (Drums, Bass, 2 x Guitars / Keys and all Vocals)
Drummer was always on ears, but whole band went IEM about a year ago. First trial was with FOH mix distributed to each guy with just a cheap pair of buds. We were all sold in an instant
I was a little dubious about how it might affect singing, but it was no trouble - however, it's probably important to note that we have always played (and are therefore well conditioned) with an FOH mix through monitors with no personal backline whatsoever, so it was no culture shock as we've not been playing for the last two decade with 'more me' or trouser flapping cabs. First gig was a weird experience in as much as we couldn't believe how good it was and why we hadn't done it years ago!
Ambient mics are an important part though - particularly for me needing that audience interaction / banter and being able to respond to people shouting requests etc.
We've since upgraded the desk to an all digital A&H Qu-16 which provided the capacity for us each to have our own individually tailored mix. I still use a mix which mirrors the FOH, but with the vocal raised just a little so I can hear that coming back into my ears more than just my 'head voice' if you get me. The other guys do have a little more of themselves, but it's not a million miles from the full band mix as that's what we're all accustomed to.
Everyone else still uses relatively cheap buds (£110, £40 and £20), but I did get a pair of Aurisonic ASG-2's (about £380). I see they're still not listed on their website, but they are a generic, rather than custom-fit and are astonishingly good. In all honesty, I was also happy with a £40 pair of Sennheiser CX275 buds and couldn't see the point in £1000 customs, but do appreciate that the seal is absolutely essential. The fact that the cabling etc is more designed for stage use etc is a factor, but it's not like the other guys have issues. Whilst it's hard to say that the difference between the Sennheisers and Aurisoncis is night and day, there is more 'strength' and perhaps 'capacity' in the ASG-2's and whilst I still maintain that those cheap Sennheisers sounded great, there is certainly more clarity, definition and 'power' in the Aurisonics.
I don't know if I've just got lucky all along, but I've never had any issue finding a set of tips that make a comfortable, airtight seal in no matter what set I've tried - I've certainly never felt that not having custom fitted ones has been any kind of compromise. Of course, there's plenty of tips that don't fit right and it is essential to try them out to find the right ones for you, but I've never once had the 'seal' pop during a gig and of course being the singer, jaw movement is the one thing people tend to say is the ultimate test.
If you want to try a really cheap trial set just to see if you could work with the IEM approach, check out
these - hilariously good for the money!