Ive had their summit park 15 (same design) for over 10 years and its been very warm for me. I have heard they switched to an eco friendly insulation. With that said im using a 9.4 R value mattress and car camping.I had an echo park 20 and I tested it out one night in the back yard, with joggers and a hoody on, I froze and it was only mid 40’s overnight. For context, I have the sea to summit either light extreme pad. For me, I would shy away from the echo park, I’ve read other reviews that are similar to mine.
With a mattress with only a 3.2 R value i wouldn't be surprised you might get cold.
I appreciate the feedback on this particular bag. $156 shipped for the BA 20 vs $205 for the zenbivy overland 30 has caused me some analysis paralysis