Ah yes, 'the gap.' My tent has a gap between the ground and the outer tent bottom gap. The 'gap' has never caused me a problem, I've never thought that this is a problem anyway, through the experience of use I believe its actually an asset to me. From the years of experience of my tent and the numerous nights, I have slept in it, including a continuous 36-night use on the GR10 across the Pyrenees in 2015 it has really served me well. I know, again from experience that the main benefit of my 'gap' is that it really helps to keep internal condensation at bay and I believe it helps me because I like to sleep in fresh circulating air, I find it comforting. My Marmot is essentially a warmish weather tent, not a winter tent, I use my Wild Country Zephyros for that but in the last few years I have not used it much at all, I just find it very difficult to cope with long hours of winter darkness.
Even though my tent has served me well I would like to buy a new tent and I've looked and looked but just can't seem to find one that measures up to my existing Marmott, i.e. for one person, good head height, loads of internal space and so on. I also restrict myself financially, I'm not really prepared to spend more than about £250, so I know that limits my purchasing choice. My Marmot is not the lightest tent, a mid-weight I think, but it's definitely not what I would judge to be heavy.
I've had another look at the Tungston tent, I'm sure that my tent and that tent are very comparable, the main differences seem to be the size of the tents and the poles configuration.