Guys,

I'd like to have an average zoom lens for walkaround lens, at around f2.8. With such a lightstrong lens I'm not bothered with IS.
The only zoom that comes in a normal-ish average range, is the Tokina 50-135mm f2.8. photozone reviewed this lens (they stick to facts and do not express an opinion). And according to the tests they do, its actually not bad at all! Although I would have preferred something like 28-135mm or maybe 28-105 or something like that, there are no lenses available in such a zoom range that have an aperture of f2.8. I considered the Canon 24-105 which does have IS, but only goes to F4. The canon consumer lenses 28-135, also has IS and is a lot cheaper than teh L version at F4, but well, its not L-class.
The tokina so far is the only one that seems to come close to my wishes (actually, I usually use primes 50mm or 85mm). I like the f2.8 for the smaller depth of filed (with the added stop extra light being a bonus). Also teh price of this lens (in Holland anyway) is extremely cheap at 450 euros (in the UK easily 500GBP, which ofocurse is a con...)
1) Does anyone have any experience with the Tokina 50-135mm (preferably, but not exclusively with teh 5D)?
2) Is there another lens that falls in this range? I prefer a large aperture like F2.8 and I am not bothered with absense of IS. Also my preferred zoom range is eitehr around 28mm at the short end, to 100-135 at the long end of the zoom range.

Any suggestions/comments?

I did test drive the Tokina 50-135/2.8 on the 400D. Wide open performance was exceptional, excellent sharpness and color rendition. The bokeh was very smooth, and oof highlights rendered beautyful.
Putting the price in perspective, build quality is awesome. The lens just breathes endurance, though at quite a weight (~850g) related to its rather small size.

On the con side, the autofocus on my copy was rather unreliable. Approx. 25% misses on mostly static subjects (head & shoulder portrait at al) using the center / cross-type AF-point. The focussing speed is ok, and as the manual gears get decoupled when on AF the MF ring does not rotate.
As usual for Tokina designs, CA can be quite pronounced on high contrast edges.

In the end I did send back the Tokina, though when I today scan through the images taken back then, I am quite tempted to give another copy a try.

A contender in the same focal range is the Sigma 50-150/2.8, which uses HSM (~USM) focussing. It currently exists in its MkII generation, while MkI specimen are still around on sale. The MkII is supposed to give relief to some focus problems the MkI version displayed at near to minimum focus distances. Word has it that there are still some problems in that area. When used like 30%+ farther, the AF is told to be quite reliable. IQ, given the various test results, is quite exceptional. My guess is that the MkI version might be quite a bargain.

Regards,
Ray

EDIT/PS
Reading your text again, I saw you were referring to a 5D. Those two lenses are designed for APS-C and won't work on full frame or at least vignette heavily.
To mimic the same FOV on full frame, there are quite a few options in the 70-200 range, e.g. the Sigma 70-200/2.8 HSM which is very well regarded.