In the original trilogy the one big ground battle was the assault on Hoth. Both sides had reasonable tactics. The rebels dug in and used artillery and air to delay the assault. The imperials broke the fortified position with heavy armor and then poured in the infantry to exploit. Not the only possible actions, but there's no obvious stupidity.
In ROTS both armies are standing up walking towards each other as if they're re-enacting the Battle of the Somme. Sure, they did that in AOTC but at least they had the excuse that they'd never fought a major battle before. You'd think natural selection would've left someone who likes diving for cover in charge. On the Wookiee planet there were some trenches dug but then the troops got out of them as the droids attacked. Plus nobody tries to take high ground or maneuver around a flank. Any modern American battalion could wipe out both sides without upgrading to blasters. Actually, if blasters have the effectiveness they seem to in ROTS, they might want to stick with modern weapons even if they have the option to upgrade.
The space combat wasn't any better. With the brains they can put in droids you'd figure they could have long range missiles that put anything David Weber's written to shame. Nope. Instead they have capital ships shooting at each other at distances that would make Horatio Hornblower say "If you're that close shouldn't you be tossing some ropes over?"
Anakin is a heck of a pilot though. A ship with no lifting surfaces, whose engines broke off, and is losing pieces in reentry, and he still has a controlled landing. Impressive.
R2-D2 had some fun moments. Beating up the super battle droids has to be classed as fanservice, though.
What really got to me was how the population of the galaxy has no role except spectators. They're having this massive war with nobody volunteering to fight except the Jedi and lead conspirators. So the people have no say in what happens to them, other than maybe voting for a senator, and you gotta know the galactic senate is even more gerrymandered than California.
When the DVD comes out I'm looking forward to one deleted scene:
Obi-Wan: "You were the chosen one! You were supposed to destroy the Sith!"
Anakin/Vader: "Yeah! And the only way to do that is to infiltrate, so I can kill the Emperor when he least expects it!"
"But I can't get away with it if he thinks I'm still friends with any Jedi."
"Oh. So shall I whop off some limbs, set you on fire, leave you for dead, and run off with your wife?"
"Yeah, that'd be a big help."
I think at this point I really want Peter Jackson to outlive Lucas and inherit the rights so we can get a remake of the Star Wars saga that's done right.