It's a bit of everything, but yes, nicer hubs make a difference. White Industries hubs are very nice hubs and will be trouble free and roll wonderfully for as long as you have the wheels. The A23 rim is also very nice. You don't say which model wheel you had, so if it's a low end model, there will be a big difference for sure. However, it's pretty much a given that a nice, well made set of hand built wheels made just for you will always ride nicer than a stock or pre-made wheel that is intended to work for a large variety of riders. If the bike feels good now, just think how nice it will ride once you get rid of those Gatorskins.