Quoted from Tuna_Delight:

After having played SW Premium/LEs, going with a Pro and not having the hyperdrive loop (or whatever it's called) would be a real bummer.

Quoted from frg:

Objectively DI is the winner by miles. But - for me personally - it is just not fun to play this machine. The only "real thing" are the SIM cards. Modes are good, multiballs are more punishment than reward for achievements, especially pointwise. You play one minute - 100k, play five minutes 500k... only exception, get SIM cards, so that you have a multiplier for the modes. Don't get me wrong, not only points matter, but - points are rewarding... I need this rewarding feeling during the games. But as stated - my very personal opinion. Two more comments - even on max. power the flippers seem pretty weak compared to the current Stern machines. Lightning is awesome (much better than on Sterns).
Star Wars - what a theme and what a disappointment... who needs 40x, who needs the design flaws (fork ramp, hyperloop) and who needs this unispired layout? Those were thoughts... until i bought a Pro for price I couldn't skip. Oh man, what - literally - what a lightweight, also in terms of quality and playfield "population".
BUT - after some games and more knowledge about what to do and when to do it... this machine is a blast, it rocks, it's super fun. Why... soundtrack is great, it flows but still it is a shooter and most importantly it has the special moments, the rewarding moments. Having 40x while destroying the Death Star or getting a hyperspace up or... is so much more rewarding than everything I saw on DI. The speed, the brutal force - awesome. You have to be focussed all the time keeping your multipliers alive and in the correct position. This really adds another level in gameplay - like it or not, for me it's great.
I sold my DI after two weeks, I also sold my SW Pro after 4 weeks. But the only reason to sell the Pro at this time was to upgrade to a Premium. Well adding extra cash also adds the already mentioned design flaws. Why should you do this? Well, it seems the "flaws" were at least minimized with the code updates AND I wrote about the special moments - the go to shot is the left inner loop shot which is on a premium/LE not anymore the inner loop, but it feeds the Death Star/Hyperloop by the fork ramp so you can enjoy these moments much more. Getting a 1.8b hyperspace hurry up results in a short break in which you can enjoy the animation and the achievement. On a Pro the ball fires back so quickly, you may often have not even the time to check how many points you got
Both are outstanding machines, but it depends on your pesonal preferences... SW Rock'n'Roll - DI hmmm maybe Jazz.