The ganking was pretty bad, but to be honest not enough to really slow things down. Overall, the ganking Might cost you like 10 hours total, which isn't much for 10 days played and a 100 days at level 70 being able to gank anyone you want. A lot of people will gank multiboxing groups because they think they are bots, or they think they are being heroes. Then, a lot of people will just do it for the same reason a lot of your own faction will insult you - they come from the "you're doing something interesting and I'm not" camp and they resent you for it.

What made it 10x worse for me in outlands is I ran around ganking everyone I saw on a server with more alliance than horde. That got me camped by multiple 70s. Even then, it cost me very l ittle playing time. I quit ganking around level 65 and now most people leave me alone.