I was an EMT/ ER Tech. Best 2 years of experience I could ask for. I got so much experience in the ED, I'm way ahead others in school, and the teachers and classmates notice. Sure, I get made fun of for my constant "this one time in the ER..." stories, but its all in good fun. I agree with the others- EMS is definitely different, but the skills you learn are often an asset, no matter where you work. No offense to RNs out there, but have you ever seen a nurse try to backboard someone? Its just a different specialty with a different skill set.
Its interesting, the more EMS work I did, the more I loved working in the field and questioned my RN career. Well, my roommate, who is just finishing his medic program after giving up on nursing, said he doesn't really see a good future for himself. Around here all we have is fire-based EMS, so to be a medic in the field (ie: not doing general transport), you need to get on with Phoenix Fire or surrounding crews.
I think you're making a good call by going for the RN. Hey, in some states, you can actually challenge the NREMT-P and get your medic after your RN to have both. Makes an easy second gig for overtime and stuff (actually heard that from a FF when we got to discussing our careers on a call once). I'm looking into doing this when I'm done in May. It also helps with getting a flight nurse job if that's a route you'd like to pursue.
Good luck bro!