On the flip side, I found the Macro option provides a really startling level of detail up close. I also found the combination of the f3.5 and Image Stabilization to be of great use in low-light, indoor shooting where flash is prohibited. It's a fairly fast-focusing lens, too.
Even though I have upgraded to an L-series lens, the 28-135 is still a personal favorite. Considering it is 1/3 the price of an L-series lens, I cannot find a single fault with it. Anyone looking for a general-purpose lens for under $500 to compliment their Canon Digital Rebel, Rebel XT, 10D or 20D has found it here.