A very effective and fun spell within SR with a dualled F9/Mx. I played with a party of six, and the combo of Improved Haste + BBoD + TS made the F/M outshine every other party member against dragons in TOB. SCS2 improved Abazigal Lair was almost a breeze Though I guess you didn't want to give additional awesomeness to the already overpowered dualled F/M ? It's true the spell doesn't seem that appealing to multiclass or singleclass Mages.
But you know, some players like to play with your wonderful mods, and also like playing with cheese