I have a L7 Air Savant, with Maximise Spell. I can achieve very good SP economy by only using the Shocking Grasp SLA, with Maximise on, but the cooldown is just long enough to be inconvenient. If I use my other spells with Max on, though, I tend to burn through my SPs quite quickly (e.g. Lightning Bolt is normally 9SP, 34 with Max for only double the damage).
How are other Savants handling this? I'm tempted to just leave Max off most of the time, doing less damage with the SLA, but able to throw other spells around without breaking the SP bank, and only use Max when I need to go nova on something.