I had some durability issues with the soft gel tips and had to get them remolded into acrylic. Apparently my ear canal was a bit too narrow, causing the soft gel tips to rupture and effectively tear apart. The guys at 1964 were awesome about it though and did the remolding for free within a 1 week time frame. They even refunded the cost of the soft gel option without me asking which was pretty awesome.
Anyways, my two cents: in terms of general use, both the acrylic and soft gels feel equally comfortable to me once they are in the ear. When it comes to insertion and removal however, the acrylic tips are a bit more rough. The soft gels also held a slightly better seal when I'm laying down flat on my back (sleeping); the acrylics had a tendency to fall back (the seal is still good however) while the soft gels had a slight bit of suction that held them in place. Besides that, there really isn't that much of a difference other than the fact that the soft gels are softer and more malleable once heated.