Originally posted by bdery My bad. It must have been another review site.
I re-read Pentaxforum's review of those two lenses, and it seems there are some optical differences, mainly regarding aberrations. But the XS fares well indeed.
The reviews here, and elsewhere, can be a bit subjective. The XS is a cheap plastic kit lens, the Limited is a shiny metal lens containing the word "limited", thus our perceptions change. The more you spend, the more you value something, and the more you highlight its qualities. I take the reviews here with a grain of salt, they are subjective views. I'm a macro guy, so I find most of the "sharp" lenses reviewed on the internet to be "soft", but I also find some of the more poorly reviewed lenses to be great. There also is some variation in quality, the comparison of the XS and Limited here is a good example, the Limited was a bad copy, and was inferior in every way to the XS they had.
That said, I continually kick myself for buying a grey market DA L 55-300, just because the lack of quick shift. Quick shift is worth $100, to me at least. But this too is a bit subjective, since I've found I generally prefer manual focus, which probably goes back to the fact that I mainly shoot macro.