Most people will say the 2800 was the most reliable. We had a 2400 hour TBO and we could get two 100 hour extensions. I think maint pulled the screens, checked compression and did a valve lash check for each extension. Had many pulled at 2600 still going strong.
The 3350 and 4360 just had too much going on. There were plans to make a turbo-compound 4360 pushing 5000 hp.
The 1830 does OK, I never had much luck with 1820s. Figure each cylinder on a 1820 does the work of a C-150's engine and is bigger.
They took a lot of work to operate but that's all we knew. Then I met a RR Dart.