Forgecage is a heck of a lot more expensive though. 1,500 gp in ruby dust, ouch!
Though you can replicate it via greater shadow evocation (8th lv spell), thereby eschewing the need for a costly material component. And I don't think the 60% real drawback affects any part of the replicated spell meaningfully (how do you have a wall of force that is only 60% effective in blocking?).
So yeah, maze can actually be interpreted as being weaker than greater shadow evocation...
I suppose maze would require you to rethink how you design encounters though. In the very least, it discourages the use of dual-monsters of roughly equivalent cr with moderate cr, such as 2 death giants, since you can expect one of them to be mazed, and the other giant to be taken care of by the time maze wears off.
But then again, I could also argue that this may not necessarily make the battle any easier, since it would discourage the use of AoE effects (as you can only affect 1 enemy at a time). So depending on how your party fights, they may not really be any better of (not forgetting that maze itself already uses up a 8th lv slot).
It is also quite powerful against the party as well. Taking the party cleric out of the fight can pretty much turn the tide of the battle. But no fun for the player who effectively has to sit out the entire battle.
