PJ, The Keron 3 GT model has vestibules on both ends with a small hooded vent on each end, the hoods can be left open even in the rain. Each hooded vent has a solid panel covering a mesh panel, and both can be zipped open for max air flow, i.e. no mesh, nothing stopping the air flow. Both front and back doors have solid panels covering mesh that can be unzipped to just mesh.  Top and side of the tent body are solid breathable fabric. Plus you can leave the vestibule doors open on both ends in nicer weather. That said the fly comes down to the ground, as do most 4 season tents. I wouldn't say the ventilation is their strongest point, but it's OK.

I've used it in Q late May early June, and the October trips mentioned earlier. And we do get hot days without wind on the arctic trips, but there you really need the solid storm protection.

It's 16.8 ft long though, so you need some room for it. But a huge tent with 2 vestibule areas at 10# 9 oz., the larger vestibule is 73" long, the other end has a 42" vestibule. For 2 people it's a Taj Mahal. Not so sure it's necessary to have all it's protection unless you were extending the season more. But Martha likes it as a sanctuary from the bugs and weather. She's happy, I'm happy.