I remember a long time ago when praying and all other skills had a delay implemented to prevent people from praying like 10 seconds to get things that take 10 minutes to get now. The unfortunate result of this is a very obnoxious cap on HP and SP regeneration. The fix from before that limited just praying is now limiting HP and SP regeneration and people wonder why there isn't much difference from wearing a regeneration+1 ring and a Ring of War...
And to clarify... yes I'm posting this because it takes 10 whole minutes of waiting to recover all 602 of my SP.