Image Quality - 17-40 L vs 20mm f/2.8, 28mm f/1.8

Once again I'm debating about getting rid of my 17-40L and moving to Primes. I definitely like the speed, f/2.8 vs f/4, and I'm also tired of the CA I get with the 17-40mm. I can only assume that much of the CA is due to the 17-40 being a zoom. (Well, mostly my shooting habits, I know.)

How would you compare the image quality, barrel/pincushion and CA of the 17-40 compared to the 24mm f/2.8 and 20mm f/2.8?

Also, how about the AF speed? I do like a fast focuser....

Any comments, opinions, and facts are greatly appreciated.

I am at the point of deciding on primes or the 17-40, I have already discounted the 16-35 due to quality.

The 24/2.8 is ment to be very good value, myself I am looking at the 28/1.8 due to the USM and FTMF and speed. The 28/1.8 has had some bad mouthing but it seems OK on the only reliable reviews I have seen.

The 20/2.8 again should be quite good but has even more bad mouthing than the 28/1.8, also the 17-40 in size, weight and cost is not so different from the 20/2.8.

The primes should have minimal distortion and, at least for the 20, lower CA.

Reviews to check out:
http://wlcastleman.com​/equip/reviews/17-40/index.htm
http://wlcastleman.com​/equip/reviews/28mm/in​dex.htm
http://www.photozone.d​e …ses/canon_28_18​/index.htm
http://www.photozone.d​e …ses/canon_24_28​/index.htm

You might also be interested in these Canon MTF comparisions:
http://www.zen20934.ze​n.co.uk …les/20mm_Region​/index.htm
http://www.zen20934.ze​n.co.uk …les/24mm_Region​/index.htm
http://www.zen20934.ze​n.co.uk …les/28mm_Region​/index.htm
http://www.zen20934.ze​n.co.uk …les/Wide_Primes​/index.htm

I was just consider getting the 17-40L or the 24-70L. I do weddings and events so I need the wide angle side. What would you recommend? I have two primes so I need something wider than 50.

I would ask one of the other wedding photogs, but I would think the zooms are a better bet than primes for this.

I have the 28/1.8 but have never owned or used the 17-40. I do know, though, that the IQ overall from the 28 prime is better than that from my 24-70L at the same focal length and f-stop. In fact, the 28 1.8 is probably my favorit e lens at this point...it is fast USM/AF, quiet, solid, nicely sized and just wonderful images. All that said, when shooting events, including weddings, I use the 24-70 reserving the 28 for posed shots or the dimmest of lighting.

Checking this stuff out - particularly the links from Lester - I may just get the 28mm f/1.8 in addition to the 17-40, just to have something a little wider and almost as fast as the 50mm f/1.4.