Blast furnance is one of the worst bosses I have seen in years. Could just be me but I detest these "90% add fights", they're so incredibly boring to me. Atleast spoils had some variation with the adds, but here they just crammed in so many annoying factors into one boss. And the main culprit (atleast for me) is the security guard. Now, they are not hard to deal with, but they just add a silly annoyance to the whole fight with those darn shields. It's not fun what-so-ever to constantly having to tank adds out of these shields every 10 or so seconds.
So far Blackrock Foundry is one of my favorite instances, but that god forsaken fight is the thing that just drags it down for me. What's your opinion? How did you find BRF as a whole, and do you have that one boss that is just a major pain in the &%! to deal with? Please share.