Y'all gots gud parsh? Heckin' dang, I love gud parsh. However, these are both great car choices.
People complain about 944 maintenance, but it's not that bad if you just take care of junk before you get to the track. Make sure the clutch still grabs at home, and is in fairly decent nick for the next race. It's a day-long job since you've got to drop a bunch of stuff to get to the clutch but that's a day better spent with a six-pack at home that will give you some peace of mind at the track. Also, pay attention to the timing and balance belts as it's an interference engine, and also the water pump since that's behind those stinkers. If you have any doubts in those, replace them just in case.
The upside to that shortlist of fiddly 944 maintenance items is the wealth of knowledge from it being a fairly popular track car. Clark's Garage is basically the Bible of DIY 944 fixes, the forums are decently well-traveled and it's not hard to find a Dane-glish rip of the full factory service manual, either.
So, I'm going to call the 944 the boring choice, given that it's a fine Porsche race car with its own spec series. You're not going to win any masochism awards unless you show up and your clutch goes kerblammo on practice day. Then HEROIC FIX IS YOURS TO LOSE!
I threw my spare clutch in a box with skulls and crossbones and a big "NO!!!" written on the front, and hide it in the truck for race weekends. That seems to have warded away that evil for now, but I still don't 100% trust it. It's going to go someday. This might be my off-season project to tackle, if I ever scrape up a new job.