Yeah, not being critical of it, just thinking out loud... you're basically guaranteed much better results and a more chilled out time of it.
Trying to get something done in a given 24 hour period means you can't spend 24 hours on the music, for a start... although if you don't sleep, eat, fap, poo, etc. it could be pretty exciting to hear the results.
Also you've got much less opportunity to reflect on what you're doing, nut your way out of apparent impasses, take a break when you're fucking over it, etc.
I'm thinking I'll give the 24 hours real time version a go, because it's the constraints of that particular challenge that sound like the most fun to me. It'll have to be the last weekend of the month if I do it.