It's a tough choice. I'm currently flying EMS in helicopters, but trying to scratch and claw my way into the charter FW world, which is proving hard to do with my experience, and without taking a very drastic pay cut.
With that said, I am home at least some point every day, depending on if I'm the day pilot or the night pilot. I live 20mins from my base, and work 7/7 12hr shifts. We get 2 weeks vacation a year, so I can be off a month no sweat.
It sounds nice, and it isn't bad, but it is seemingly more dangerous than FW flying, you are "stuck" in the same general geographic location and usually visit the same handful of hospitals over and over. I fly very nice equipment, and the "down" time is similar to a firemans quarters(living area, bed, kitchen,etc).
For me, I am looking to the FW side for a safer, and hopefully more lucrative job once I get some more FW experience. I also think il there are more job options if you fly airplanes. This EMS stuff is gonna go bye bye I feel like at some point, at least at the level it is now, and I don't want to be on the street with no other skill set to fall back on. God forbid I have to get a job that doesn't involve flying haha!!!
Hope this helps somewhat, and doesn't sound negative in any way, because the EMS side of RW is really not a bad gig, I'm just the type that has to be doing something all the time, and there is a little too much down time for me. We only fly about 150hrs a year if that.
Any other questions feel free to ask.