That looks like a solid list, my only concern would be the lack of troop choice. I was going to run 2 in my 1000point list but ended up with 3 and footslogged it. It was a doubles tourney but aside from that the list I took did very well against anything that was thrown at it. This was for 5th edition, to be fair I did not fight any horde armies, so I am unable to comment of that portion of the game. This was my list. Sidenote, Saint Celestine was the MVP every game, and the seraphim are an auto include for me now.
Total Roster Cost: 1000
1 Saint Celestine, 115 pts
6 Seraphim Squad, 170 pts + Two Inferno Pistols x2 + Seraphim Superior
Troops: Battle Sister Squad (10#, 145 pts)
9 Battle Sister Squad, + Meltagun x2 + Sister Superior
Troops: Battle Sister Squad (10#, 145 pts)
9 Battle Sister Squad,+ Meltagun x2 + Sister Superior
Troops: Battle Sister Squad (10#, 145 pts)
9 Battle Sister Squad, + Meltagun x2 + Sister Superior
Heavy Support: Exorcist
1 Exorcist, 135 pts
Heavy Support: Exorcist 1 Exorcist, 135 pts