I have a Mac Mini hooked up as a home theater that I finally updated from Mavericks to Yosemite. I don't have a mouse or keyboard and control it exclusively from my Macbook Air (which works fine under Yosemite.) Right off the bat, under Yosemite, the cursor response is laggy and applications seem to take their time in opening. Video playback seems fine once started. At first I thought it was an issue with the monitor connection (connected to TV), but it seems to be set up properly. I did run a speed check over Safari on both computers. For the Macbook Air, I'm seeing download speeds of 50-75 mbps. The Mac Mini has been as high as 30 and as low as 5. Checking with Activity Monitor, there doesn't seem to be a resource hog. Any suggestions and what particularly can I try only using screen sharing?