Boars have sperm rods, but girls can get ovarian cysts - having paid for a spay and resultant after care, I know what I would prefer to deal with, sperm rods are easy peasy (just breath through your mouth not your nose lol)
As someone earlier said, judge the animal not the sex. With horses loads of people say mares are difficult, stroppy etc etc., then they meet my Doey and change their minds!
I have five boars, three have one wife each, and the other two have three and four wives. All of them are lovely boys but equally my sows are lovely too. My Whiskey who went to the bridge last October was a sow and she was more laid back than one of my boars - it is all down to the individual.
Would love a pair of boars next but worry the girlies around would upset them, we will see what happens in the future, the 15 here are keeping me busy enough right now!