I’ll be placing an order very soon for my Spring 2019 Nuc and I have mixed opinions, for and against on both.
What are your views and opinions on both of these breeds?
I understand the pro’s and con’s for both but I thought i’d just put the question out there to help me come to that deciding factor although I know in the end it’s up to me.
I’m in the U.K.
Many thanks all
Get two hives and have one of each. 
Seriously though, if you can only have one, I would choose Buckfasts. Just be aware that if ever they swarm and you end up with a daughter or grand-daughter queen later, they can get quite nasty. The original colony should be fine, if you go to a reputable supplier, but once they cross-breed, their offspring can be very feisty. 
That second gen feistiness seems to happen with carni’s as well. My overwintered hive queen was from a carniolan swarm cell and they get worked up very easy. I’ve been stung 5 times by that hive this season, and only once from my 12 other new hives.
Some of them are very persistent as well. If I’m doing a full inspection I suit up completely knowing they are going to get worked up. During my mite counts a few weeks ago I was in full suit including long gloves and one of them managed to get in under the glove and sting the back of my hand inside the glove.
On the original topic of buckfast vs carniolan I currently have both, and after a year with them can’t see a big difference. Both seem to build up strong colonies quickly, build beautiful comb honey, and are very gentle. It will be interesting to see how they perform through the winter here.
Ha! I know for sure that i’ll be up to two hives in no time Dawn! 
and the Nuc will be from a well reputable dealer who i’ve already been in contact with. He has both Carni’s and Buckfast. They’ll be overwintererd, health checked and ready for Spring. I also read that its wise to be prepared to re queen in their second/ third year with to keep them sweet. Would you agree?
I think i’m swaying towards the Buckfast at least to start off with…
Definitely. Hives with queens 2 years and older are more likely to swarm and take your nice queen with them. They don’t always, but it is more common with older queens. 