Initial impressions are pretty good. The thing is pretty heavy but that's to be expected given it's really nice range. Unfortunately I was only able to take some shots with my living room lighting but I'll grab some other stuff this weekend. I think I'm going to be pretty happy with this lens though. It is really nice to have the additional reach. I don't think I'll be getting rid of my 16-70 since that's really a beautiful lens but I think one could be very happy with this lens and whatever prime they like best, mine is the 28mm f2. Still this one should be really convenient to bring to family stuff and other outings when I want to keep the kit portable.
I also got the Domke F-8 bag and while very little, it fits this lens on the body and has enough space in the main compartment to have one or two primes if you lay them horizontally. Or this lens vertically and the body with my 28mm on it on end. So that's pretty much exactly what I was hoping for. The pockets on the side are could enough to carry some cloths and batteries too, not sure I can get a rocket blower in there though, maybe just one prime and the blower though.