One of the things that bugs me about some of the TOS sets are the computer terminals. Some of them (like the briefing room console) are fantastic---sleek and minimalist in design that suggests advanced tech. Others, though (basically a box with some old-fashioned looking lights and switches like in "Courtmartial") look really dated, and they did so even back in the '70s when I first started watching TOS.
The thing about the Jupiter II
interior design is that it looked/looks somewhat near future. It could seem believable (from a '60's perspective) of something we might see within a century. A flim like 2001: A Space Odyssey
also has that kind of feel to it.
Good design can often transcend its era. The interior of Klaatu's ship in The Day Earth Stood Still
remains a great design for an alien technology and partly because it's presented in black-and-white. Klaatu operates everything by hand gestures and without obvious familiar controls or instrumentation.
The limitations of budget and resources resulted in inconsistent efforts on TOS. In broadstrokes it was usually brilliant, but once in awhile the limitations would give us something clunky.