One lingering question in my mind is to go with a Canon 17-40L instead of the Tamron...benefits would be build quality, usable on FF camera, and faster focusing. But I would sacrifice some reach, low light shooting, and pay an extra $20.
As always, I'd appreciate any input or suggestions...
PS. This thread is for shorter distance general purpose only -- I have a Canon 85mm f/1.8 and may get other primes (50mm f/1.8 or f/1.4) to cover indoor sports. I will get longer zoom(s) for outdoor sports.
It sounds like you need more coverage than f/2.8...
With your pick there's too much of an overlap between the 28~50mm range. Another option is an EX series, the only one really full-frame
Super Wide zoom with HSM (faster focusing and full-time manual overide) which'll work quite well when you upgrade (at least for me):