Best unit in the Codex, IMO.
I--contrary to many Fraters--have been disappointed with Death Company overall this edition, even after the Codex dropped.
Sanguinary Guard, on the other hand, are pound-for-pound extremely effective. Especially with the 5+++ from the Standard of Sacrifice, they are hardier than their lack of invulnerable would imply. I like to run them with a Sang Priest as well so that they are both getting back up after being slain and wounding T4 on 2's in melee (not bad at all). In fact, with Sang Priest support, using swords they wound everything on the game outside of FW stuff on no worse than 4's. Not bad.
Couple overall thoughts:
-without a native invuln, their survivability in many ways depends on the size of the unit. 20W in a 10man unit is march hardier than it seems
-unless Captain Slamguinius is just too good to pass up, you can get creative with them by having them off on a flank on their own with a Sang Priest or Ancient as WL, thus spreading around the re-roll's with their Heirs of Azkaellon ability. I personally like to make The Sanguinor my WL so he can run with the SG, boosting them considerably, while also being a bit of a Distraction Carnifex: Old Goldy (The Sanguinor) provides amazing buffs to them, but is not as crucial to my army's success as the enemy may think.
-especially if you're not going for max resiliency (10man unit, Standard, Sang Priest, etc...), you do need a plan to keep them alive since they will draw fire. Most people opt for the Descent of Angels way to keep them completely out of harm's way until the time of their choosing. However, don't forget the Classic tactic of using Rhinos to block LoS while they jump up the board.
still fantastic MSU hunters. 4man unit is fantastic at chopping up everything that doesn't want to be in combat, including multi-wound Hellblaster and equiv.
B. The LVO (since this seems to be the most popular tournament build)
C. All-In (my preferred choice)