I am going to add my 2 cents here. I definitely prefer moulds. I have Phonak Paradis and the bass is marvelous - never heard that with my Widex’s. I now only have domes - waiting for the moulds to come in next week.
The problem with domes, is insertion. If they are just “in the ear”, I find I am losing alot of sound. I have to take care to precisely insert them into the canal and then the sound is wonderful.
I opt for moulds so that I can get that insertion done easier and avoid sound loss. Of course moulds can wiggle out a bit but a simple tap puts them right back in place. The domes take much more effort.
Its all about the interface. A great aid with a sub-optimal interface , is useless.