How are these Tokina lenses?

[Tonghang Zhou]

Any one had experience with these two lenses?

    1. 24-40 F2.8 TOKINA AT-X A (72)
    2. 28-70 F2.8 TOKINA ATX AUTO FOCUS (72)

How good are these compared to Pentax lenses's optics or build?
The speed of 2.8 is quite appealing.

Thanks, Tonghang