Yeah, the saturn, much like the PCE, has tons of great stuff -- including a number of shooters -- that weren't ported over to the western markets, so you definitely want access to Japanese games. And I also agree with Zeta, switching's the way to go (and the 2-way JP/US switch is waaaaaaaaaay easier than switching a PCE/TG16. It does get a little more involved once you get into a single 3-way region switch).
Some other reasons for going switches > PAR.
- You don't have to flip through the PAR menu every single time you start a game. Maybe not a big deal to some, but it started getting annoying to me.
- People often complain of the PAR's thicker PCB wearing the saturn cart port out quicker than using official carts (though to be fair, the saturn cart port sucks no matter what).
- And of course, direct save access + ability to play ROM cart games as Zeta mentioned.
Here's my main unit -- 50/60 Hz region switch in the left, which isn't really necessary for North American folks unless you wanna try out some EU games (on a 50Hz capable TV). 3-way US/EU/JP switch on the right.

And I thought PAR worked well for ALL 1MB/4MB fighters (except the old ones not working well with Vampire Savior, IIRC). From what I understand the whole graphic glitch with some SNK 1MB games only happen if you use the official Sega/Capcom 4MB memory carts. I could be wrong on this one, and I'm too lazy to go and check for myself.