At last mat purchase, having decided that the Neoair original that I'd been using wasn't up to all season use, I took the view that the difference in failure reports on assorted fora between Exped and Thermarest was enough to choose a Neoair XTherm, which was much the same in insulation value to a Downmat 7.
An added advantage is that inflation by mouth isn't really a problem if the pumpsack gets forgotten, and that down-spitting isn't going to happen.
At the time there were insufficient reports from SeaToSummit or Big Agnes mat users to form a view on them.
When looking at insulation, I'd take the view that about R=2.5 would risk being inadequate during the October-April period when a frost may happen, and I sleep relatively warm.
Note that R-values come in ISO units as well as the more common US units (BTU/hour/Sq. foot, deg F). The difference is such that 1 ISO = 6 US, so check if the number is in the 1 to 1.5 range.
As for inflation pressure, is "knees just stop bottoming out" when kneeling on the mat? If so, I'd call that too hard.
I generally aim to compress the mat to about half thickness when in a side-sleeping position.