Okay, so the folks at Comply were hardly monomaniacal (they were pretty much the opposite of that), but I suppose one could get a bit high-and-mighty — the in-ear monitor crowd owes quite a debt to the sanctity of “the seal”, and Comply makes the tip to help make that happen.
Being more of a custom man myself (he says, as he shrugs into a custom-made Field English), I tend not to explore universals, but I will admit that this predilection is rather limiting (and sometimes, extraordinarily slow). So, if universal-fit you must, then good isolation (and fit!) are a must, and that’s where Comply comes in.
Tyll Hertsens of Inner Fidelity wrote up his trick for getting the fit right, and I’ve found he’s right — these tips, mounted well, are “invisible” (not muffled) and tend to maximize bass response (because they seal). You can get a bunch at Amazon.
What I didn’t know is that Comply also makes wraps for custom-fit in-ear monitors as well. Why? Because your ear changes — not over time, so much as across the day. Your fit may well be great, but it may not be so great when you want to smile, for example. Anyway, for those that are curious, these wraps work almost exactly the same as the tips — they improve the fit and/or seal. You can find them at Amazon as well.