DS has managed a whole week without his laptop. He's coming home next weekend to collect it so we'll have a quicker meet up than planned. 
I actually found it less difficult taking him back this time as when he was home it was like nothing much had changed except he seemed a bit nicer, if anything. More grown up and chatty, less teenagerish and grunty. I think he appreciates all that's done for him at home now that he has to cater for himself at uni.
Also I did see him on 4 occasions, he came home twice and I visited twice, so much more than I was expecting. Taking him up in October, it felt like I was losing him but the reality has been much better, so this time I was much more relaxed and so was he. He also knew what he was going back to and he's been enjoying it mostly.