Need to give it a try, but I can't imagine it being very comfortable to play on a handheld. I've played MH3U on Wii U, and it's quite fun but I reckon I could only enjoy it for a long time if I had friends who played too, as teamwork is super important. Also it's a tad grindy when trying to get materials for crafting, so it reminds me somewhat of an MMO but with engaging combat. It's awful playing single player, and online randoms are shit. Though if I decide to get the New 3DS, I'll get MH4U with it.
But might wait for the Toukiden remake/sequel on PS4 in March. Looks like faster paced Monster Hunter but with Japanese folklore monsters.
Got MH4U yesterday, just doing all the weapon tutorial quests to see which ones most appeal to me. Mostly doing solo, so think I'm going to mainly use the Switch Axe and Gunlance. Hunting Horn seems interesting, but probably more useful in multiplayer when you can buff your entire team.