Well, if you must include one of these in your army, I'm not going to stop you. I agree that they're great for adding a little character and they're good fun for friendlies but you have been warned because, in my opinion, they're a bit rubbish :)
It all comes down to their reliability really and their vulnerability, the very 1st stat on their profile doesn't get them off to a great start...
Movement 2D6 !
So, you might charge 2 inches or maybe 12. I guess on average you'll be going 7 inches (because for anyone who hadn't realised it yet, the average roll on a D6 is 3.5 inches).
I guess, they can come in handy but they can also be lost in the first turn of combat, or worse still, taken out with missile fire.
It's a poor choice for your rare uit really, especially when you can have a G I A N T !!! :)
Yep, more on the B F G in my next post*
notes:
the "F" in B F G does not stand for "friendly" :)