I've also got a pair of Ultimate Ear's monitors which cost a lot more, and the Etymotic's are probably about 9/10 as good for sound repro, and 7/10 for isolation in comparison.
Yeah, they fit as well as those yellow foam earplugs do, and are equally good at blocking out sound, even when not switched on. To remove them you have to pull the cable as there's nothing else to grip hold of, definitely not a problem with any of my FF lids.