Re: I'm a touring drum tech and the time has come for IEMs.
My 2 cents,
I'm in the market too. Here's the thing with the SE215's, they're affordable and reasonably well regarded. Everyone's ear canal is different but when I have used universal (as opposed to custom) IEMs, the foam, earplug like seal they provide is really good, which is what you really need. Trust me, PROTECT YOUR HEARING NOW.
But there is a price.....they are difficult to remove and replace. IOW, if someone needs to talk to you while you have IEMs in, and you can't understand them, you have to remove them. Then to reinstall, it takes time for the foam to reseal in your ear.
But if you're going to put 'em in and keep 'em in for a full show, they're really great. You should be able to find foams that fit in the assortment in the box and then get a supply of them....because they wear out when they become soiled. They're less than $20 for 5 pair, I think. The rubber tips are more like regular earbuds and don't seal as well, but they last.
Custom IEMs seal right when you put 'em in, which is one reason why they're better.
The problem I have with customs is that I'm concerned about sound quality, and it is impossible to know what a CIEM will sound like until you've made the investment.....and if you're not fond of it, they cannot be resold...because they're custom. It's a frustrating fact of life. Im going to post about specific customs and see if anyone has anything to share.
I hope this helps.