hmm, dont want to stoke the fire, but streetjibs has a point, the first zoo frames had some pretty poor welds. The one i saw had bits of welding rod sticking out here and there, bad runs, grinding marks etc. As he pointed out, that was the first frames of echo and zoo, and lots of them broke (es and em series, lynx etc.)
deng is a clever man, he's making frames for peanuts, selling them for a fortune, and each time we get bored of a brand, he makes a new one and sells a shedload more frames for very little design change.
In any case, i'd rather have a well thought out frame than an innovative one thats been made for innovative's sake. Almost all aluminium frames have the same front and rear triangles, just different tube forms, dropouts and gussetting. Steel is limited by the conservative outlook of the main tubing manufacturers, thats why most steel frames look the same, its not through want of imagination.