Installation: no mounting worries because I have removed my motherboard to remove the old (plate behind the motherboard to remove) therefore quite simple in my case for laying new. I did not find that the attachment was as fragile as I had read in other comments.
Noise level: Quiet enough and in line with my expectations for a PC to office use and web browsing. I recommend to those who want a PC utra silent.
Cooling: no worries with my P4 and a desktop user!