Unfortunately we only get 2 units to choose from and neither of those is a Psyker Battle Squad. I guess these Elysians really do hate psykers. Oh well, what's a boy to do.
Storm Trooper SquadronNothing new or exciting here stat or option-wise. The only real difference here is that you can't take a Chimera, so no scouting melta bunkers any more. They can choose a Valkyrie as a dedicated transport if they wish. Well since you'll need to get out of the transport, where you're likely to die, this isn't a great idea. Too many points wrapped up in too fragile of a package.
Bottom line- move along, nothing to see here.
Drop Sentinel Squadron
Now this is where things start taking a turn for the sexy. Remember how Sentinels compete with cool stuff like Vendettas, Hellhound variants, and Valkyries for the FA slot? Not any more ladies. They've been moved over to the Elite slot where they don't really have any competition. Technically they can also show up as troops, but we'll cover that tomorrow. You can now feel safe to take these with impunity. Plus, these aren't your Grandma's Sentinels either. They're loaded with all sorts of usefulness that they never had before.
These have the same stat line and cost as scout sentinels, but lose scout. They come stock with a heavy bolter and can...are you ready for this... FUCKING DEEP STRIKE. Shit yeah! Now is where I start getting excited. Well not excited about the heavy bolter, though. It kind of makes me miss the lowly multilaser. So here's what we're going to do with that- upgrade the bitch. You can do a heavy flamer for free. Great for cities of death, but not so much for regular 40k. But, for the price of a power fist you can upgrade to a fully full on full blown multi melta!
In my mind the best use of these little buggers is as a suicide melta unit. Drop in close to your enemy, wreak havoc on their vehicles, and laugh as your opponent wipes them off the board and you advance the rest of your army unscathed. When else have you ever seen Sentinels make somebody shit their pants and jump up to the top of the target priority list? Did any of your Sentinels survive? Time to shoot more shit and tie somebody up in close combat.
If you don't want to deploy on the field or deep strike, you can also take a Valkyrie Sky Talon as a transport. Kind of a meh idea, as the transport lacks much in the way of firepower and you already have a fairly reliable way to get your walkers to more or less where you want them: deep strike. I'll cover the Sky Talon in more detail later.
Any more upgrades? Yeah, but seriously, why would you spend more points on a throwaway unit? You can get camo netting (super expensive) and then I will punch you in the throat for eating up all of the retard sandwiches. You can do a searchlight, but this won't matter as you will never deploy these on turn 1 anyway. Smoke launchers go into the maybe category. If you're doing heavy flamers, you'll need these to survive. You could also throw hunter-killer missiles on if you're into that kind of thing. Good when used with flamers, but not as good with the meltas. You're probably going to want to attack different things with missiles than meltas. Plus you're still guard and your BS still sucks ass.
Bottom line- awesome throwaway unit. Put a multi melta on them and call it a day. Go after key armor targets after deep striking and prepare to lose them after you pop whatever your target was.
I think taking pairs of these will work out best for you. The squadron rules will hurt your survivabilty a little bit, but your BS is shit, so the extra shots will statistically guarantee* you 1 hit per unit. 1 isn't too threatening and a full squadron of 3 seems a little like overkill.
*a statistical guarantee is not legally binding. You can still miss.