I have a 3DS and a Vita, and if I had to pick one to play forever it would be the Vita.  It's just a shame that it doesn't get much love from Sony anymore.  Not sure if you're a PS+ subscriber, but you should look into subscribing because you'll get at least 2 free games every month, plus they do a lot of really good deals as well.  I just picked up the Tales of Hearts game for $5.99 last week, which is a great price.  

Dragon Quest VIII was my first and still by far the best Dragon Quest game I've played.  I wish they were doing an HD remaster for the Vita or PS4 instead of the 3DS, but I guess I'll take what I can get.  Excited to play VII though, because I never played it and it's the only one besides X which never released here that I haven't played.

Yeah the fusing is what I remember not understanding. It made no sense. Also, the amount of times my characters missed attacks in combat was infuriating.