I have/had both. I500 third flipper shot is a one trick pony. TS has three shots from it. I500 is a blast to play and is the best integrated theme this side of WCS94, imho. But having both in house, I couldn't get into I500 as much as my Shadow. I500 was moved along. I believe you will regret swapping those two.
Congo and Shadow compliment each other nicely. I've never played Tommy. The Shadow Knows!