Quoted from Mr_Tantrum:
I am so tempted, but I've never done a playfield swap and just trying to think through things to determine if I want to undertake such a project.
Having done my Gorgar - it can be a decent challenge. System 6 boards have the benefit of only having a couple playfield looms making it somewhat easier to test the playfield outside of the machine. Same can not be said with the WPC series unfortunately. Nice thing about this game is that there are no drop targets to tweak. I had a hard time lining my drop targets up on my Gorgar. Pop bumpers were the next largest pain point. With removing and relocating so many wires you're bound to come across problems to troubleshoot no matter how careful you are.
This probably isn't the hardest to swap compared to more complex playfields. Though I can't speak at all to mounting the rail hardware as the older Williams ones didn't have any. I've heard this is one heavy playfield if you're taking the existing playfield out without taking off the super charger.
Should you decide to tackle it - plan on 80 hours, and I found it very useful to push playfield pieces into insulation foam board in their rough positions so that it made things easier to match up parts later on.
That being said, I would do it again. It'd be between this machine and my FirePower to tackle next.