I don't know what you define as 'deep' but WPT is certainly one of the (if not THE) most *strategic* pins ever, shot-by-shot. Many strategy options with each shot, with incredible integration of playfield layout and rules. Far more coherent than the stack-a-zillion-random-modes TSPP, and strategy is a bit more focused than WOZ. 4 (5?) multiballs, a few mini-wizard modes plus the "Poker Valinor" Keefer Invitational, incredible flow, tons of drop targets, great 2" flipper play, etc. This game is way more than 'underrated.' And, it has a nice open playfield so it is very approachable for novices, yet the strategic subtleties and skill required (shooting lanes and ramps that start way up the playfield is much harder than shooting closer ones) make it a consummate game for the expert that won't get old.
Yeah, just some more of my effusive praise for WPT, probably my favorite game, period. (Yes, I own a WOZ, CV, LOTR, etc., and have played pretty much every modern pin.) BTW, people who think a good WPT strategy is to lock the ball on the mini-pf and then just hit it to start a multiball don't get it...
Also, WPT is fast as heck. You *did* remove the top left orbit gate and disable the flop/turn posts in the settings, right?