Roger, A very good article.
You mentioned the enclosed tent with the doorway opening into the vestibule. This is one of our (the wife's and mine) big concerns. Rain and snow are a problem. The wind driven rains we get in the NE corner of the US often swamp the entranceway in our Stephensons forcing us to keep a bandana handy for wiping up. This is a real concern, because it also adds to internal moisture, hence condensation, to the inside. I would confirm that an enclosed entranceway is important, especially in bad weather. We discussed an option for putting two doors in the sides (where we now have large vent "windows") to be protected by the roof awning, but have not gotten to it, yet. In the Sirius, we get in and take off our shoes, before getting into the tent body keeping things cleaner and dryer.
One large advantage to using tunnel tents (we have three - Exped Sirius, Stephensons 2rw and The North Face Dyad 12-sort of) is the mode of sleeping, we have found. With the 2rw we crawl in, then turn around. With the Sirius, we simply crawl straight in. Two years ago, while camping in the 2rw, I happened to "knee" the wife in the chest while spinning around. This has become one of the things we look at. Besides being easier, it is much safer...at least from the wife's viewpoint. Headroom for sleeping as well as sitting are important, with a large preference on straight-in sleeping modes. It looks like your tents do about the same as this, much lighter, though. The Dyad is a real snuggle encouragement, not really large enough for two.
There are a LOT of advantages to a tunnel tent. The ventilation is good, generally. This is usually offset by the fact that manufacturors often put smaller vents in them. For two walled shelters, this matters little. But for single walled tents, it can make a difference.
In fall and spring mode, the Sirius, allows us to pack the fly and poles, only. My wife cares not for seeing 'coons or 'porkypines eyes staring at her from atop her sleeping bag, soo a tarp is out. The weight is a bit, but not like winter.