And that's why you take D-weapons and Stormswords. No cover saves!
I was never impressed by the Stormlord when it came out, for that reason. When it stands still it can do some decent damage, and the idea of carrying 9 or so obliterators on it that can each pick different targets is a nice one - but I like to advance, and so it's not my thing.
A Stormsword, though? Blows chunks out of an ork battleline that depends on its shield generator. Same with D-weapons. A Shadowsword would make short work of that big mek as well. And my reaver's really getting ready to put the hurt on some greenskins once it's completed