I'm not going to over sell it to you. In a away, the themes and even what the villians represented are pretty much outdated in this day and age... though it might go back to it. The special effects are out dated too.
There are somethings I do want you to consider. Star Wars helped finish what Star Trek started. Before these two shows, Science Fiction was not taken seriously as a means of story telling at all. It wasn't even given enough credit or respect to make any amount of money back. Sci Fi movies of the time, if they even got it that far, were sold as spaghetti westerns in space. Even the original star wars "a new home" was laughed upon. The Theaters didn't even want it. And many refused to play it in their theaters. Fox had to "tack it on" to another movie that was considered to be a more "safe" hit.
The result was obvious and because of the success of Star Wars and Star Trek, we now have Science Fiction taken a little more seriously.
Don't watch the movie in the mod to have it "impress you", because it probably wont. In terms of action, it can't go one on one with the action found in Scott Philgrahm, Matrix, Or even 1, 2, 3. The action is handled differently, and the lightsaber battles were not as fast paced as the newer movies. Not because "luke was a beginner" or "vader was just a head on a robot body" but because they were using actual fencing styles baised upon actual sword fighting styles. The fighting from ep 3 was the result of a man (can't remember his name) that Lucas hired to create the fighting styles. And if you watch the method of fighting from ep 1 to ep 3 you can see it. The final battle in ep 1 was more connected to the fight style used in the Original Trilogy, only with more money at his disposal, and younger actors, he was able to take the time to actually teach them how to fight, and thus, the moves were more fluid and faster.
Having someone FORCED to watch something is a sure fire way to ruin the movie for them. I'd say, sure why not, watch it. Its a fun movie, incredibly quotable, it has legends like Harrison Ford, Carrie Fisher, and Billie D Williams, so you know the delivery is going to be there. But i'd suggest just relaxing and enjoying it.
In all this overhype and dramatic "what ROCK have YOU lived under" the whole purpose OF Star Wars is lost. The point is to have fun watching it.
So if you do decide to watch them, sit back, relax, and pop a bag of pop corn, and just have fun.