I wouldn't say that Telechips isn't capable of making decent ARM processors... I'd be more wary of some random generic Chinese Rockchip stuff in that aspect (they didn't even have a license to manufacture ARM chips for the longest time). I'd guess a quality Cortex or an OMAP would be the most reasonable choice, though, in the long run.
But yeah, it's all about implementation. Cowon messes up some details, generic OEM Rockchip devices mess up some other stuff. The whole Android thing is still not ready for prime time, in my opinion. That's why I use my netbook, a truly excellent EEE 1015PN (2x Atom N570, 2GB RAM, 500GB HDD, ION2/GMA switchable via Optimus), for most things on the go. Android things are really crap in comparison, or any other tablet/internet device thing, for that matter. I guess we're still a few years away from the point where tiny touchscreen jack-of-all-trades don't suck.
to your Thread you posted i'm going to share a thought of words
i really think COWON rushed to get into the Android world and they have failed with the D3. also, the price for it is just unbelievably high. hardware wise i don't even want to go there at all. Telechips just needs to stop and let Rockchip take over. i hope COWON learns from the D3 and thus' hopefully comes up with a BETTER Device with good specs. but at a more reasonable price