Good to see this topic discussed. WrathOfAbe has put it together what I have experienced so far since R265. Wanted to downgrade but some of my projects were already saved in later versions.
Was happy to see R277 being released. On my mid-range PC with 8Gigs of Ram it still crashes regularly. But at least it now takes some time. If I have an open browser or other ram swallowing programs running it will crash if I Alt-Tab over to or out of Construct. Sometimes just by clicking something in the editor. Same if I have more instances of Construct running. Always having my fingers crossed when I switch windows. Not exactly... most of the time I forget to save and this makes it pretty annoying. :-p
Funny thing is right now - it works like a charm. Yesterday I was upset enough to install R265 again and after a while of pondering about I revoked my decision and installed R77 again. Now I have three instances of Construct, one program is test running in NWjs and an open browser with around 20 tabs. Opened the image editor, tabbed over, another image editor (still running?!?) then deleting some frames... writing some words in the forum, switching over and it works, whiskey tango foxtrot?!
I will test this further but today it looks surprisingly good.