Woo! I got my Mk IV Ironclad Dreadnought from Forge World a couple of days ago, and I loved it. It's a stunning machine, looking really imposing and aggressive. Of course, the chainfist and close combat arm help with that. It was fun to paint as well, being the biggest mini I've painted so far. I especially went for the close combat stuff, since it fits so well in my army. I'm still waiting for the base, which I ordered from Dragonforge. I'll post up a pic when that's done, but I couldn't wait to share it as it stands as of now.
You may remember one of my first minis, a terminator, was called Brother Vermis. But since the guy he's named after is a good friend, I decided the Ironclad fits him much better. ;)
Anyway, as for the weapons loadout, it's all really aesthetics for me, since there's no one to play in my area. I can just go for what I like really, hehe. Anyway, I've completely fallen for dreadnoughts. After playing around with them in DoW: Retribution, I really have taken a shine to these mean machines. I can just picture Brother Vermis drop-podding into a group of heretics, and his augmented voice booming out: "I have come to eviscerate you." I think I'm going to get another dreadnought. ;)