Is this the f3.5-4.5?
If so I have one, I used it on my film body.
I like it, it's quite small and compact and light and the USM is nice and although I've read critisisms of distortion I have to say that I never noticed anything significant and had no complaints. I say had as I've recently sold my film body but I kept the lens. I've tried it on my 20D and it seems perfectly fine although with the x1.6 it's not such an attractive thing on APS-C.
£199 seems a bit steep though, I think I paid about £150 for mine, from Ffords I think. I bought it after missing out on a few ebay Cosina/Tamton 19-35mm's.