Purchasing a new lens, need a second opinion

[Payt]

So it turns out that this lens is only going to cost me 350 plus tax, which is a great deal and half the price of similar lenses I had looked at. What I'd like to know is how the AF speed on the Tamron 28-105 f/2.8 roughly compares with the stock 18-55 lens' AF. Is it twice as slow? Four times as slow? And is it twice as heavy?

I'm also looking for a good wide-angle lens for a Canon camera to sort of coincide with this Tamron. Like, 10-20mm or something in that relative range. Any suggestions?

 

[Payt]

Alright, so the whole deal with special ordering the 28-105 with the discount and such got real messy, and after hearing about the slower zoom I was slightly more hesitant. I ended up settling for the Tamron SP AF17-50mm F/2.8, which I have been very happy with after the first few uses. I also picked up a circular polarizer along with a UV that I needed anyways, which seems like a great investment.