I know I am really really late to this. How did you go?
Personally I feel the advice of the H100i was not the best. I have one and it is really good but I am looking to switch to the Glacer on my next build (started out as a second pc as I had heaps of parts laying around and is quickly becoming a beast).
Have a look at this, for future reference: http://www.hitechlegion.com/reviews/cooling/liquid/37574-cm-glacer240l?showall=&limitstart
It is about the most accurate review of the difference between the two, performance wise.
Don't get me wrong the H100i is a great AIO cooler, up around the top rungs of the ladder but the performance AND the mod-ability of the 240l, I believe, put it that one rung up. The hands down winner.
If you bought the H100i, you must be very happy with it and rightly so.
No 1 now, though, has to go to the Cooler Master Glacer 240L