I need a new PSU... Advice
I have a 690 as well and while there's plenty of room behind the mobo tray, the exits along the side are lipped and the slot for the cables to get from the PSU to the back of the Mobo tray is to far aft. I have all the grommets and edging to modify this issue, but just haven't taken the time. It has oodles of room, but as you stated, the finishing thought on a good base for cable management leaves a good bit to be desired. My suggestion is grab a Dremel (or similar) and modify it to match your cabling needs. The layout is great for cable management and a little work with the Dremel would make it perfect. The orientation of the HD cage is perfect for cable management, but IMO hurts the air flow. I'll try to remember to get you a quick cad drawing posted tonight if I can get that rig up and running. It has my Cad on it and it's still in the corner not running from the move. I love both my 690 and my pair of 590's. Lots of room and great for air flow. Not so good for stock cable management.