I use .net core by day and rails by night (side business) and I can honestly say .net core MVC is kind of influenced by rails (not a lot but like 30%). After more than a year using both I found more joy with rails.
I find Rails gems and ecosystem to be more mature also ORM is friendlier since I felt more comfortable using active model than EF
All of the above could be a personal preference since I worked on rails for a longer time. At the end of the day I got to an end product with both
However I use .net core with MSSQL and on a Windows machine.
I've used rails back in the 3.2 days and after 7-8 years I still can't find the simplicity of rails in .net core and I really wish it was the case. I'll bet getting a rails 6.0 project from first scaffold to fully working site with admin interface and login system would take just one night of work without really remembering anything. With .net core, no idea how long. I saw some code generation commands for the most recent versions, so maybe there is some hope for .net core.
.net core works fine with postgres. Though I tend to use Dapper rather than Entity framework. I just use .net core as a REST backend / host for a vue front end.
There's always a bunch of pros and cons to comparing languages and frameworks, I'll just say neither are really going to hold you back from doing anything.
Does anyone have experience with both?
I’m especially interested in how .Net Core works with Postgres on Linux.
Most of then tutorials focus on using the entire MS stack.