Ive never worked yet with these guys aside from Arteezy. I can say Arteezy is the kind of manager who keeps following protocol and that's what makes him a good manager. Ive only heard of Yahoo as one of the best manager, or maybe the best of all but never try to join with his campaign yet.
But many of my friends admired him that much, so I can see also how he operates and clearly a professional. Murat, is also nice manager even though he still just starting to handle btc paid unlike from prominent here like Yahoo and Hhampuz. But these guys are all good in all way if you would compared to others that launching campaign.