Easy answer since ive owned both but the GnR was a SE but ive played the LE version...Mando LE for the win! Its the better shooter, alot better code, and for me the better theme. I do like GnR though just isnt JJP best layout or rule set but sure is pretty and has some good moments.
Mando is full of modes and breadth in the code but has some bugs that still need worked out. The mini is so much fun and im usually a upperplayfield hater. The diverter shot, left ramp, right ramp, and even the horseshoe orbit are all satisfying shots. I enjoy it more since I enjoy mode based story games. Mando feels like im in a battle with the machine.
GnR is all about score and risk reward and Im not really much of a point chaser so it didnt click with me. The jackpot scoring reminds me of BM66 but i feel BM66 does the jackpot score chasing alittle better with the modes telling a story at the same time but as I said I enjoy mode story telling more then point chasing. Shots wise my favorite shot is the extra ball shot and when i played the LE the upper playfield definitely added another good aspect to the overall game.
Both games have super nice looking playfield art but GnR is better and more interesting looking with some really good drawling's . GnR easily has better lighting but I prefer the white hotrails over the colored ones since it makes the ball easier to see. Cabinet wise Mando LE got the win and the mirrored backglass is really nice looking. Its sorta pick your poison situation. Do you like point chasing or mode playing.