When reviewing a LOT of resources, scrolling through the scheduling tool is current a rough experience. This will improve with the next release that eliminates the horizontal bars in the collapsed mode and having overbooking turned red.
But, under-allocation is just as important as over allocation. A conditional format that allows me to see resources more easily that do have the bandwidth and/or are underutilized is very helpful. Many people process info this way vs. using the planning tool which is not tailored to visual processors.
Another related feature would be sorting the resources based on their likelihood of matching a selected opening. Right now I have to hit the magic wand and go on a scavenger hunt.