the h50 is pretty ez to install and is almost as straight forward as a reg aircooled HS. install heat sink to CPU...mount fan/radiator...done. i wouldnt recommend getting it though...a top of the line air cooled HS would work better and is ezer to maintain then this.
there are alot of problems if you want to watercool a computer and ill list them out
1. leaks (can ultimately ruin your whole computer if it leaks on teh right spots)
2. if pump dies...my pump is almost silent and so if it died i wouldnt even hear it *i just recently set up a waterfall res that i can see waterflow in my case now =)
3. growth in your system...stuff can actually start growing in your loop if you dont have biocide...it can start clogging up your radiator and waterblocks and greatly hinder your cooling capabilities.