Want something better than the 75-300?

I'm currently in the proccess of doing a multi lens shootout with a bunch of consumer telephoto lenses.
It'll be awhile before i complete it but here's something interesting for those that aren't happy with the canon 75-300 lenses-

I see B&H have several Tamron 70-300 LD (1:2 macro) lenses in perfect condition for only $100
http://www.bhphotovide​o.com …c=&Submit.x=17&​Submit.y=8

Maybe someone want's to try one with little risk of losing out (you can probably sell it for a little more on ebay if you don't like it)

I've only used one example of this lens so far but it's impressed me quite abit.It easily beats the canon 75-300 for sharpness and contrast (especially at the long end where the canon is lousy)
It also flogs my sigma 70-300 Apo macro super II at the long end (but my sigma may be a dud....damn stigma quality control)
I'm not sure how it goes against the canon 100-300usm as yet.I don't have one right now but one is comming next week.

Any drawbacks?
Focus is obviously abit slow.
It gives some purple fringing-a touch more than the canon 75-300.This will bother some and be unnoticable by others.
The bokeh (background blur) is abit double edged

Anyway i better stop yappin away
I was just intending to give a heads up in case anyone wants to grab one while B&H have some 2nd hand ones