From what I've seen, Rosarius saves more often than Mantle.
If you're doing things right she has a 2+ invulnerable save. spending that many points to buy her a 4+ invulnerable save is a waste. On the other hand - if she gets shot enough one hit is bound to sneak through even a 2+ save - and one STR6 wound is all it takes to kill her without a Mantle of Ophelia.
Celestians are meant to sweep into combat a step behind my Serpahs. I play against a lot of people who run CC armies, so we usually meet for CC in the middle of the table. With AoF, these Celestians have mauled Tyranid Warriors! Though I would like to capitalize on the number of Evicerators I have in the unit... love em.
Celestians on foot can't 'sweep' anywhere, and if you're fighting CC armies it's even more important that you mech up to stay out of CC as long as possible. Sisters are just plain bad at CC.
I believe that at some point your Celestians waded into a unit of Warriors and took them down. Once, my Canonness was charged by a Daemon Prince and killed it in a single phase, taking no wounds. I'd be foolish to count on that ever happening again, though.
When joined with a unit of Storm Troopers, he can.
Yes, he can in that case.
Kitted my Superiors with BP and CCW because those are the models I have. I've never really had a problem with these getting into CC, but just in case that extra attack from Vet is useful.
Of course you've never had a problem getting into CC - your enemies know they are better than you at CC and try to get there asap. If you have two spare sisters with bolters, use them as Vets. One extra shot from the bolter is worth more than one extra attack from the CCW.
How is the book useful if most of my units will have a 9-10 Ld anyway? I am notorious for rolling low most of the time, so Ld has never been an issue with me.
Actually, you roll perfectly average, just like the rest of us, but you have the Gambler's Fallacy, and probably the normal human habbit of only remembering the successes, not the failures. Also - when the 'nids have just torn up five Sisters you no longer have Leadership 9, you have leadership 4 and slim chance of passing that test.
True, no arguments here... just don't know where I could scrounge up the points.
Well, your Celestians and that rosarius aren't doing anything. Convert the Celestian sqaud into a Battle Sister sqaud, that gives you more troops and frees up a mess of points.
Really that's the best STs have for ranged mob support.
But Stormtroopers aren't for ranged mob support and trying to make them do it is only going to prevent them from doing the only thing they're good for.
Once again, whenever I've used Seraphim they've always proved useful. Bustin tanks, scrappin with boyz, or in one game where they took down a Necron Destroyer Lord in one turn, losing only one model.
Again - do not confuse statistical anomalies with predictable results, and do not trust your memory. They are not worth the points. I run two squads, but I like the models, I'd never claim they are good units.
This is all sounding pretty negative, but it's assumed that if you're posting an army list, you're looking for criticism. That's pretty much why I don't post army lists. I know what I want to play and I care more for fluff and fun than optimisation.
Your main problem seems to be trying to make units do things they're bad at, and building to shore up massive, gaping holes with small bandages. Trying to make Sisters good at CC is just never going to work. so don't. Instead concentrate on being a powerhouse in the 6"- 10" range where you are already strong. Do it right and the few enemy models that ever reach CC are much less of a threat.
Same goes for Stormtroopers. They have exactly one reason to exist - a squad of five is cheaper than a squad of ten Battle sisters. Their job is to go to ground next to your home objective and hope the enemy don't have flamers. Trying to make them do anything else is only going to frustrate you.
If my advice doesn't mesh with what you want to play (or the models that you have) then be good you should ignore me - but this is not the place for fluffy and fun, it's the place for optimising...
Oh, and remember - the dice have no memory, and the human brain tends to only remember those times when something unlikely happened.