Icy Dock has built a new hard drive cage which can be used to fill up your remaining optical drive bays.
Icy Dock's Black Vortex 4-In-3 HDD Cage Arrives : Read more
Icy Dock's Black Vortex 4-In-3 HDD Cage Arrives : Read more
Agreed, I'm currently using one of Icy Dock's 5x 3.5" drive backplanes (still fits 3x 5.25" bays), it's completely tray less and works a treat, other than the pathetic fans it ships with (I swapped two tiny, noisy 60mm fan for a custom mount with a 120mm fan, works perfectly now).After years of using these things I ONLY use "trayless" hotswap racks, and the power and data connections must be opposite side of the motherboard tray. When the sleds break, or the trays fail you are SOL and must buy more sleds/trays from the company for a premium price.