Should i get the Tamron 17-50mm f/2.8 XR lens? Advice needed.?

I have the Tamron 17-50 f/2.8 for Nikon. I am pleased enough with the performance that I use it on a D80 for weddings.. I also have a 19-35 Tamron that is a fine lens, and cheap, although not quite as fast. I used to have an older Tamron 28-200 that was really dismal. I gave it to my daughter, and she ran over it with her car. She claims it was an accident... :-)