Returning to this thread after a few years with KZ10 IEMs with Comply foam tips. Last Saturday I put them in and felt there wasn't a good seal - even without anything going through the IEMs the background hubbub of the venue was distorting, and once we started playing everything was loud and uncomfortable, and I was struggling to hear the pitch of the guitar and vocalist. Time for two things: 1. replace the foam tips and 2. shell out for some customer IEMs that are going to give me a better seal. My budget is going to be around £600, which should be good for something like the ACS Evolve, Bellos X2, or Ultimate Ears UE6. Much as I'd love to trade up, I don't think I can justify 64 Audio A3s. Anyone got opinions to offer? Will I get a better seal with the silicone that ACS use rather than the hard acrylic of the other manufacturers? Should I be concerned about the lack of dynamic drivers? Have ACS still got a bit of a reputation for unreliability?