Finally ! Goodbye php,ruby and go ! can't get rid of Python though, simply the best language for analytics.
(I use Python at my day job, and C# on my own side projects at home. F# seems... interesting).
For example in the 1.0 release the ORM is a complete joke at the moment. It can't do fairly basic stuff, like worse than ORMs from 10 years ago.
These days, it's really very, very good. And it's been amazing since EF4, for about 5 years now. Trying to push it too far is a mistake and can cause performance problems, but, as with all ORMs, sometimes you need to drop down to raw queries.
In all honesty, if you have a well designed system it's pretty good at what it does. I've used it without any issues on small personal projects and it was great at what it did. Although getting it to work with Postgres is needlessly "complicated". Not complicated per-say but not as easy as it just working with SQL Server.
What happens when you take a legacy system and move over to .Net and try to use EF on a poorly architectured data model? Chaos.
"Oh you want to search for orders that have these attributes that are stored in a bit-encoded string field that is only joined from 3 different tables?"