Never played any of the FE games prior to Heroes, but I like the exp loss if you die. Being able to adjust your team and strategy is key to games like these. I mean, cmon, where's the challenge, really.
I played Everquest back in the late 90s. When you died in a certain area of the zone (map), you acquire experience debt and your corpse would remain where you died. You would then have to RUN BACK (depending on what city you're bounded to, like a checkpoint) to your corpse in order to get that loss of exp (but a fraction is only returned). Sometimes it can take 10 minutes to get your corpse back, sometimes 10 days IRL. Sometimes if you end up dying on the corpse run, now you have 2 corpses to recover and even more exp debt lol... Hey, I'm no stranger to such challenges...
TL;DR : Welcome to a world where challenges exists. FeHeroes is JUST FINE THE WAY IT IS WITH EXPERIENCE.