Does anyone have an experience with the Thermarest Ventra down comforter and/or the Thermarest Down 35 blanket?

trying to figure out what the main differences are. One is rated for 40deg other other 35deg, but judging from some online reviews the down blanket is not as warm as it its rating.

i am looking to use it mostly for car camping and the occasional back packing trip in New England in the summer and fall. It may be connected to another when car camping. Not sure which would be the most durable and best band for the buck.