Apples and oranges, space is the only thing they have in common (and, at that, it's two very different universes, species wise, physics wise and in terms of set-designers too). One's an epic quest to the heart of the immortal battle between good and evil, the other is - as originally pitched to Lucille Ball after she let finally Gene Roddenberry into her office at Desilu and said: "In one sentence." The reply: "Wagon Train to the Stars."* True story.
a) real actors - Harrison Ford or William Shatner? Alex Guinnes or DeForest Kelley. Really? And Carie Fisher was not only hotter than all the women of Star Trek, her scene on Jabba the Hut's sand-ship alone is hotter than all of women of Star Trek combined.
b) Real Director - few things are more powerful than a single artistic vision. Trek because of the TV series deal had lots of writers, even more re-writers, and different directors. Wars had Lucas. The difference is huge. Wars is one consistent product, while Trek is highly uneven, ranging from Awesome to Camp.
c) Real Money - Movies or TV? Oh, I don't know, how about the difference between sleeping in a doorway on cardboard vs. staying in a luxury suite. TV is about cheap, cheap, cheap - making movies is an exercise in spending money that gives the big-money boys at the Pentagon a hard-on. That difference is pretty damn clear too. Trek is, because it is, kinda cheap, shoddy, all gimmick and no depth. Trek sets look like, because they are, put together with the '40 foot rule' in mind.** The Wars sets are still considered visionary. The models even more-so. Nothing was done on Trek that could not be done on a sound stage (cheep) and Lucas only used sound-stages as a last resort preferring the infinitely more expensive location shooting.
No where is this more apparent than in the aliens (pretty much the heart of any space saga). All the aliens on Trek look like really bad college theater projects with latex, but the aliens on Wars, the Ewoks, Chewbacca, Jabba - those things are truly theatrical magic because they are good enough for you to actually think they are real. Think on that for a bit.
Interesting theory about Star Trek is that it's a very thinly veiled parable of the Cold War with the US (The Federation), the USSR (Klingons) and China (Romulans). {interesting note: my on-line spell checker has Klingon in it, but not Romulan, humm). It's all very much a graduate school drinking game but it's kinda fun to play.
* - Props in the real world to Star Trek, which had the first inter-racial kiss on network television.
** - Broadway sets pretty much set this standard. They are built and painted so they look right from 40 feet away, you get close up, it's like kinda icck. Elvis's stage costumes are the same way. So is your favorite metal band, those amps, mostly dummies.