Warhammer 40,000 – I picked up a few variants of the Razorback turrets for my Twilight Ravens, it's pretty useful that they cost the same as the Lascannon which means I don't have to tweak my lists in order to use them. The twin linked assault cannons will work great with the Stormlance formation that I've been running lately. I like the punch the lascannons provide but a few extra shots could make he world of difference against hordes of dudes.
The Lascannon/Twin-Linked Plasma Gun option is a bit odd, having more shots is nice but the no twin-linking on the lascannon reduces it's effectiveness, especially with the way I've been rolling lately. However they look really cool and I'm looking forward to testing them out.