[Baalz]

Just like everything, astral shines in some situations and falls flat in others. Astral is, however, widely considered to be one of (if not the) the strongest school. The pure astral caster can cast soul slay, paralyze, and enslave mind which are all wickedly effective against concentrated, elite troops (ie the ones you usually have to most worry about). Stellar cascades is an underrated spell IMO, there isn't much it can't decimate once you get critical mass of casters. Horror mark won't win you a battle, but it can make the other guy sorry he did. If you're looking at cross path astral spells gifts from heaven is great, astral fires isn't too shabby, and neither darts can tear up anybody with low MR. Keep in mind astral casters can also form communions and one guy can cast light of the norther star to boost everybody. Boosting your astral path will give you a penetration bonus to help with the MR roll most astral spells have to overcome.

If you're facing large groups of chaff troops it's hard to beat fire evocation spells. Air (lighting) is good against smaller, tougher opponents, but is easily counterable (lighting resistance) at a certain point. Astral has no solid counter, fail a MR roll (which you will eventually do if it's cast enough) and your SC just got soul slayed no matter how many hps he's got...