I'm a big fan of mids and currently have and use two (Duomid and SL5). I had a Wild Oasis with the netting and I used it a lot, but less than 10 nights in deep snow. I loved the net, though, for here in the Southeast where we don't see much white stuff. Neither of my current mids have perimeter nets, but I'd consider adding them if I used them in the bug season (I hammock when it's warm, so these are mostly winter shelters for me).
Whether or not the net sticks in the snow depends on the type of snow. If it's wet stuff that eventually freezes hard, you will have a heck of a time pulling the mesh out. One time in horrendous winds, though, the holding power of the net in the snow was actually a bonus. In the morning I was usually able to kick the snow holding the net and it would pull out pretty easily, but I recall at least one time where it was a real pain and wouldn't release and I ended up packing chunks of snow that were attached. Around that time I spoke with John at Bearpaw about making me a mid with perimeter net that was attached a couple inches from the bottom of the silnylon and had clips all around to raise the net up so it wouldn't touch the snow, but could be lowered for normal use. I never pulled the trigger on that, though. I still think it might be a good idea.
Regarding the rain wicking, yeah maybe, but if you use a ground cloth it's not really an issue. Especially in a big shelter like a SL3 where you most likely won't touch the netting anyway. I would make sure the corners angle inward slightly. It'll keep the mesh out of the rain and mud.