Tokina 11-16MM F/2.8 ATX 116 for Canon Opinions/Results?

I'm using a Canon T2i and I'm looking to add/upgrade my lenses and a wide angle is one of them. At first I was looking at the Tamron AF 10-24mm f/3.5-4.5 SP and then I was shown the Tokina 11-16MM F/2.8 ATX 116. It's a faster lens which I like, slightly less distortion, better build and the camera store rep who's a pro and knows me said the IQ is better. The sample shots I took outside only on streets looked very good on my PC.

I mainly want to use this for landscapes and occasional group shots.

Any opinions on the perfomance and IQ of this lens would be appreciated. It looks much better than the Tamron.

Thanks,
Mike