yes I did. I followed their instructions explicitly and the audiologist who took my impressions also told me to use the bite block and explained their purpose. So unless my impressions became squished during transit (possible i suppose) then perhaps the lab technicians may have taken off too much material? I don't know.
But, honestly, after I applied my own wax fix solution it sounds a trillion times better. I'm listening to Ottmar Liebert's Binaural album "Up Close" and I can't get to sleep. It's that good. And it's 3am now
the purpose of the biteblock is to 'open up' the ear canal a little, but that is not the case for everyone. Some people's middle ears shrink down a bit so it is actually the other way round ie. taking the impression with your mouth close. The SLA solves this problem but it costs tons of money though.