That is a good point regarding wounds. Nearly everything got a boost in wounds. Even Commissars. But Bullgryns and Ogryns stayed the same :-(
It's the case with a couple 3-wound bruiser units, I think. Same thing happened to Bloodcrushers and Tyranid Warriors.
Anyway, I don't think these guys require a great deal of finesse to use--stick them where you think a countercharge will become important (near an objective or near some key units) and wait for the enemy to come close. Then, whammo!
Also important to remember that they have Frag Bombs even without the Grenadier Gauntlet, which gives them a modest shooting attack. Indeed, in general I've been finding grenades to be a nice firepower boost to most units--definitely an upgrade over the old small blast template.