My advice is… both.
Zortrax is one of best machines for styren based materials (HIPS, ABS, ASA, PC-ABS) and even if you achieve same or even better quality on some models with Prusa, Zortrax do it without effort almost every time.
If you think about composite and exotic materials, then Prusa is the choice. It needs much more setup and experimentation effort, but you easily could master carbon or glass fiber filaments and 2 materials prints and flexible.
I’ve got those two, and couldn’t even have imagined doing what I do on just one.