As someone who as owned a pro for a bit more than a year now, they are both great machines. If you held my feet to the fire I would say I would rather have the LE, but even the pro is an amazing game. When I bought the difference in price was already huge. And even then it would have been better to get the LE.
HOWEVER, I love my pro. It is a really fun machine, and I have not regretted buying it for a second. I love the gameplay of it, and really that is all that matters. I've put about 850 games on it so far, and the nice part is that I don't worry about how many plays it has. If it was worth twice as much I might start thinking that I play it too much and that it hurts the value.
So if cash is burning a hole in your pocket, the LE is fantastic. And if you are on a normal budget, the pro is fantastic. Stern has done games since then that the difference was much bigger. The difference between AC/DC pro vs premium seems HUGE.