Slaphead : This is my second year with Old World Carniolan's. I have two hives and have found them OECs) to be quiet gentle and forgiving. I will often remove the top covers and perhaps pull a single frame without any protection. I don't wear gloves whenever I fully inspect the hive apart. Its seems that they build up fast in the spring (although) I don't have anything to compare them to. In our area of the country, most of the beeks have Carniolan's or Italians. From what I can tell, when we pick up our packages in the spring, the Carniolans are the most commonly perhaps.
My girls wintered well and their are certainly building up quickly. From my limited perspective, they seem to be great for a beginner like me. The only minor complaint I might have is that an unmarked queen is a little bit difficult to find at first, because of her dark color. However, I've got over that. I'm looking forward to this year to see how the 2nd year hive will do.
I sure the experienced beeks have their opinions. I have noticed that some beeks seem to keep several types of bees in their outyards. I'm not sure why this is done. Perhaps it's intended to provide some balance to the outyard.
Hope this help. From my experience, I'd certainly recommend them to anyone that wanted to try them.