sorry, but ive got to disagree here. i suppose people have different reasons for buying, but i suggest you ask theirs before laying out such overgeneralized (and IMO, bad advice)
I own several kotobukiya items, and have never had an instance of remorse, or issue with quality. I understand that their is a history involving their paint apps, so i wont fault you for buying into the precedent they themselves set, but from my vantage point, theyre working diligently on rectifying it. the difference between sideshow and koto at this point (again, IMO) is size, run size and sculpt. the quality of the sculpts from koto and their interpretations of the characters have (for my money) outpaced sideshow. and thats what i pay for. besides, go take a look at the spiderman comiquette thread and see that paint apps isnt specific to koto. and i truly dont see a point to ignoring an entire brand for no reason other than to ignore it. being a brand whore is silly.
if youre in it to be the coolest kid on the block with the rarest toys, or even looking to try and make a buck on it, then stick with sideshow. if youre a completist who needs to have a complete line, then start a line and complete it. if youre in it to have some cool looking statues of characters you like, then buy what you want. because missing on a statue you want is going to cost you regardless, whether its sideshow or koto, or bowen, or gentle giant, or whatever. at the end of the day, all of these items are limited in some capacity. just some more artificially than others. and realistically, if you buy what you like, it'll look just as grand to you and probably moreso than limiting your options.
just my 50 cents