Have both, they are completely different games. Because of that I would go against the advice of saying that "you will be happy with either".

TZ is an acquired taste. Those that love it, love it.. others can find it intimidating. TZ takes no prisoners, I've had games where I've struggled to get 50m, and the next game will be 400m+ (I'm not very good). Some days I really enjoy TZ, other days I find it frustrating. You can get drains that don't really feel like your fault (particularly from the pops of death). TZ feels to me very much like a game where you enjoy it proportional to how "in the zone" (huhuhu) you are when you're playing it. TZ isn't really a game where you can just roll up and play it and actually get anywhere, you have to think about what you're aiming for, what your strategy is, etc.

TAF was my grail pin for a long time. I finally managed to get one late last year and I must say I'm enjoying playing it more than TZ. Some days I just want to play and be flattered by a more simplistic and rewarding layout. TAF has flow in spades, and if you want to just enjoy playing pinball I think it's tough to beat. Drains on TAF feel more like things I've done wrong rather than "welp that's just the way it is", like TZ. That said for people who only enjoy deeper rulesets TAF would feel shallow pretty quickly.

I would say that TAF is the safer bet if you don't know what you want, but I would suggest playing some games on both of them, or on pins that have contrasting rulesets, etc to work out what you enjoy.

The only objectively correct answer is - both.

$800 in mods doesn't mean a great deal though.. there are some seriously crazy priced mods in pinball, and TZ has arguably the most choice of them.

I've seen the pencil sharpener painted gold tailor made slot machine mod being listed for $400+ in places. Nuts.