I'm undecided.
I don't want to hack the game up, and would prefer it look somewhat original, so probably just GI for now. Or, maybe I won't install anything in there. The flashing looks pretty cool, but I don't want to screw a bunch of resistors and parts to the bottom of the playfield to make flashers work. I also like the speaker panel LED mod, but find the wiring running all around to be a bit untidy; so I don't think I'm going to do that either.
On the other hand, I did pick up an extra set of Creature speaker grilles, so I could put a new panel in and be 100% reversible.
But, I can think about it a little as I work on the machine.