The only formation that really intrigues me and my playstyle at the moment is the golden host. However I don't own 2 squads of sanguinary guards, and I'm undecided.
I'm also having a hard time justifying taking it over the SM shadowstrike kill team. A unit with 5 claws, 3 shields and 2 fists costs the same as SG with a banner. Don't get disordered, have rerolls on assault and can use a chapter tactic. These guys can take on infantry, monsters and vehichles with equal ease. SG just can't do that. They're infantry blenders, and if your enemy hides in his metal boxes, with a disordered charge you can't really even count on them wrecking a transport.
As I see it the main benefit is that you can actually get Dante into the fray. The unit without a banner seems especially weak with only 10 attacks the first round and the inability to add a priest.
There are some good formations, however none of them really cater to my collection or playstyle (Dread pods and jump assault). Oddly if you want to play jump assault, SM seems more suitable than BA right now...
I feel like such a grinch, so I could use hearing some good ideas from you guys to get pumped again!