Granted it's been a while, as due to deployments and whatnot I haven't been building (or buying) much recently... which will be changing soon I hope. But I remember always having a great experience with Sprue Brothers, and GMW was pretty solid too - plus Great Models always seemed to have that one thing I needed that I couldn't find anywhere else, so hopefully their inventory stays the way it has been. Personally I didn't think Great Models' website was the most intuitive to use, but that's just me - and it's not like it was IMPOSSIBLE to use.
Personally I think it's got the potential to be a great combination, and I'm optomistic about it.