General speed of SCCM Console and Client
Over any new feature, I'd love SCCM to just be faster in general. Just creating deployments and testing deployments is a notoriously slow process, even for a small 200 user organisation like ours.
First of all, the console itself is sluggish. There's a measurable delay accompanying almost every click. I'm not sure where the bottleneck is, but I'm suspecting it's the server-side architecture. It's bearable, but still frustrating when you're trying to get something done quickly. Replacing the clunky console with a snappier web interface (overdue in my opinion) would likely help, along with some architectural improvement in the background.
More frustrating, is the client. Refreshing policies and initiating scans, etc, is slow, and there's no feedback on progress or anything. If I'm wanting to test a deployment, there's so much waiting involved, and so little feedback for what's going on.
So where possible, please improve the general speed of SCCM. I'm sure there's a lot that can be done concurrently that's currently only single threaded. Also, please provide some means of checking progress on policy refreshes, etc. Trolling log files doesn't count as a solution.