I'm on the opposite side when it comes to D20 SW, but then again, I was always the black puppy in the batch
In short, while I liked the D6 system, it got retarded after the 6th or 7th session, because of the impossibly slow combat (Okay, I roll my 12 d6's, minusing 2 dice for a dodge and some running). Also, anything but a Jedi, in the games I've run, and played, turned into simple ferry pilots after a while. Jedi would DOMINATE any and every combat on the ground (and some ship battles too, depending on what they put into skills and such).
Eep, but I'm hijacking here..
I personally think 3e and the D20 systems are successes. 3e is a major success in both revitalizing a system that was becoming harder and harder to stick band-aids onto for the bloodloss, and D20 for giving more choices to people, and allowing folks to finally be able to both publish, or even just give away online stuff which was *impossible* to do due to lawsuits with the older editions.
Some strengths are:
Quicker combat.. Well, I find that anyway. Yes, there is a lot more choice, but my group picked up easily on those choices, and still tend to think creatively during combat (Like jumping on the backs of big things and hacking at them, using chairs and tables as weapons etc). It has also streamlined things in that all you need is a high roll on a d20 to succeed.
Guilds mean something. One thing I didn't care for in the old editions was that guilds were simply something that you paid into, and got little out of. I'm sure in one of the net full of supplements they released that some guilds offered concrete benefits, but I never found any. In 3e, you could easily make up a Prestige class that was specific to the guild, or just plunder a pre-made one that fit the situation.
Melding.. Well, for me it's good to have D20 type settings introduced, but only for my own selfish reasons of honestly having no time, or inclination to learn more and more differing rules. In my youth, I was more than able to try all sorts of systems, and had fun doing so, but I just don't have any free time anymore, and learning the 3e system now allows me to pick up the new SW book, learn the odd little differences, and then play quickly.
Gripes:
Too much material in too many seperate sources.. Sometimes there is just too much to absorb. I have a player who isn't able to buy every single book that comes out, and while I like to introduce some feats from different sources, it's hard for him to have his characters take advantage of those feats, because the books aren't available to him (*Note: I trust my players enough to let them make their PC's up at home before we start, thus one player is left out of the 'alt' feats.. I don't keep the books from him when we play together or anything).
20th level cap.. Well, ok, I consider this to be a niddly little complaint, because I've NEVER had a character grow past 6th level in the new edition, but only because of time constraints. But having a general rule to allow the gamers who can plow though levels every week to go past 20th would be cool. Again, this is just a minor complaint. I personally haven't a clue what it's like to play someone on that high a power level
Psionics not supported as core.. I was sort of disappointed by this. I'm not saying that there is lack of support. Heck Dragon and online sources have lots of new Psi stuff. But I wish there was more effort put into making Psionics a core component.
Meh, enough of my rambling.