I think Drexler's work on Star Trek Continues
pretty much illustrates what he thinks enhanced TOS f/x should look like. His Enterprise
looks really sharp while maintaining TOS' overall aesthetic. His f/x don't jar you out of the story by looking like something from a totally different production from the live action segments.
I read his cgi Enterprise
was scaled at about 11ft. as opposed to trying to make a 900 and something foot cgi ship in order to recreate what the original ship looked like on TOS in tandem with the same lenses and similar lighting. He even has his cgi model move like the original right down to touches of subtle camera shake.