It definitely is. Just imagine that when using silicone, you instantly get rid of some unwanted rub&buzz issues. Also, tone-wise, you’ll for sure have different perception when using silicone vs. acrylic IEMs. The opinions are separate when talking about this subject, because you have lots of “ups”, but also heavy “downs” when using silicone, like bad serviceability, electronic issues coming from constant moments of junctions, etc. For your first build, if it’s a custom one, try to keep the shells as identical as possible, canal-length wise, be them shallow or deep fit. If it’s an universal, use identical tubing, and you won’t have issues. Cheers!