When it comes to human hair wigs, some swear by them, others swear at them. On the fence myself in that regard. Only one of my smaller scale dolls has human hair though. On that one I haven't noticed that much difference as far as care and hair loss are concerned. One difference though, human hair care products can be used with it, while the synthetics do better with products designed to care for and condition fabrics.
For the most part I've been satisfied with synthetics. I just get mine off eBay. I stay away from cosplay wigs and stick with sellers that have good feedback. So far, so good.