What good timing! I took delivery of my medium sized Columbus Variant 1 week ago today and used it for the first time last weekend. I am 5'11" tall and didn't find the length to be an issue. The mattress dimensions on the medium size are 55" wide by 81" in length. I checked out the Mag line and as great tent as they are, I found them smaller feeling almost costrifobic and I am not a costrifobic person. When the Columbus is open, it is 59" tall, making it easier, I think, to get dressed in the am. As far as ease of sent up the columbus could not be any easier, undo the latch and give it a gentle push up and up it goes, pull the ladder out from inside the tent, and that's it. Take down is only slightly longer as you have to made sure everything is tucked in properly.
Don't know if you would use the winter hood, I have it and it stays on the tent, there is no need to take it off when you take the tent down. BTW where I was camping the temperature dropped to -16C(3 F) and not that tent made it any warmer, (well maybe the winter hood helped hold in some of the heat), everything worked as it should no matter what the temperature.
The bottom line is either would make a great addition to your outdoor lifestyle, for me, I'm glad I went with the Columbus!
Take care
Barry, from the great white north!