I recently purchased a Serenity Ultimate 4K PC from Quiet PC. The team were excellent in running through a complicated spec and gave sound advice with little to no 'upsell'. Delivery was prompt and the build quality of the box was outstanding. The is a super fast machine with Windows 10 preloaded with no issues. My only grip was that all the USB ports are located at the rear and none at the front which makes changing/adding new devices quickly a little challenging. All round, this was a positive experience and I would certainly recommend them.