I want to replace my EF 28-135 IS USM. So far I have a choice of two particular lenses, that fit my budget.
1). Sigma 17-70 (non-HSM) f/2.8-4.5. Mint condition, complete package with the hood and paperwork. No warranty. No issues with focusing, pretty sharp, just as described at photozone.de
2) Tamron 28-75/2.8. No hood, but otherwise mint. Sharp on open aperture. BUT: seller says on his 20D it provokes Err#99 after every 30 shots or so, otherwise it works ОК. His other lens (same kind) causes no error. He cannot check it with other bodies to see if it has the same problem.
The price for each lens is only 200$. Naturally, Tamron's better choice, when flawless it costs 300$+. I don't care for only 28mm on the wide end, for if my wedding photographer carrier's any successful, i will be looking for 10-20 anyway. What are the chances that this lens will work without any problem on my 30D? The seller lives in another city, actually across the country, but I will be able to give it a 15 minutes check in the shipping company office before I actually pay the money for it. Is it worth any hassle? Since I will also have to buy a 430EX, the budget cannot be expanded for 17-50 or the 100% working 28-75, though I would very much wish it could.