Very easy installation. I just drilled the 3/16" holes in the two bottom tabs of my pannier rack, then drew dots through those holes on the toolbox tab and drilled those. Installation time was maybe 15 min. Yes, your mudguard will interfere with this set up but like they say, take it off or break it off. No, this set up will NOT interfere with the rear brake bleeder valve. I tried to capture that in the photos. Looking from behind, you'll see if the suspension were to travel that high, the valve would miss the toolbox to the left.
I fit my tool roll, air pump, patch kit, CO2 kit, plug kit, air pressure gauge. It holds a lot of stuff.
A good idea might be to emboss the aluminum with your logo. Get a stamp made or something.