CSM: Maulerfiend vs Helbrute/Dreadnought

This is one that has had me a trifle puzzled of late.  Which is better: a Maulerfiend or a Helbrute (i.e. Dreadnought) for Chaos Space Marines?

To do a fair comparison, let me firstly note that a helbrute with a pair of powerfists costs 20 points less than a maulerfiend with its pair of powerfists.  They both have the same number of attacks, but the dreadnought has strictly the superior stat line, with +1 WS BS and I compared to the maulerfiend.

The extra points for the maulerfiend go toward several aspects: it will not die, siegecrawler, daemonic possession, daemonforge, move through cover, daemon, fleet.  By comparison, the helbrute has its crazed rule.  That said, the helbrute can be a superior firepower base: the maulerfiend simply doesn't use ranged weapons!  The ability to have a built in heavy flamer in the powerfists of the dreadnought is very nice indeed: the maulerfiend suffers by comparison.

But I think that's where the story ends.  The speed of the maulerfiend is terrific and a much welcome addition to the (usually) slow Chaos Space Marine army.  That, coupled with the survivability of the maulerfiend give it the edge for me.  And if that weren't enough, one in 6 basic missions in the rulebook will result in the maulerfiend being a scoring unit (i.e. Big Guns Never Tire), which the helbrute will never have access to.  So I think I'm convinced: the maulerfiend has the edge and is well worth the extra points even if it does compete with land raiders and the like for heavy support slots of the force organization chart.