Can't go wrong with either. Having been free twice before Aurum Blade is more likely to go free again if you must chose one I'd lull there.
I've only played Aurum Blade and it fun. Feels a lot like Diablo. The game's not difficult..but a few of the bosses were slightly challenging. The fast flow of the game combined with all the loot makes the game feel a lot like Diablo. You also get one of 8 different minions to bing with you (and you can level them up). From what I read, Crimsonheart is also really good. It looks very smooth, and the game has a lot of content. You have 5 characters, and I think you can have 2 with you at each time (you control one, and the other is the back up character). The onl thing that scare me about the game is the amount of grinding. Its almost in the realm of MMORPG instead of just krpg amount of grinding (to me anyways). But sounds like people who have both like them. You can ask in the Crimsonheart thread as there's pretty active members. They all sound helpful, and always trade/give items away to help each other out. Sounds like a good group.
I love Crimsonheart, personally. I never gave Aurum Blade much of a chance though, but Crimsonheart grabbed me instantly. It's a bit hard, but I wouldn't say there's grinding involved, unless you're farming materials to craft boss level (epic) equipment. There is another 'tier' of crafting - from materials obtained from normal enemies, and that is much more reasonable. The crafting in general is pretty darn good, I'd say. The gameplay itself is a bit more difficult - you will need to dodge and avoid attacks fairly often, or chug expensive potions before you get your healing character. There is IAP, but it's in Aurum Blade too, so I won't compare. In other words, if you MUST only choose one, get Crimsonheart. Aurum Blade might go free again, but both are well worth the price tag. They're the two best representatives of their genre.
