I haven't kept aware of changes to Java in the last decade, but the things I didn't like about it then were:
1. The overall architecture (with the JVM) made it slower than the equivalent C# code.
2. C# really started embracing modern language features at a time when Java was kind of languishing (lambda functions, async patterns). Java seems like it's been in perpetual catch-up since then.
(Not OP, disclaimer, I work for Microsoft and this is only my opinion).
> I haven't kept aware of changes to Java in the last decade, but the things I didn't like about it then were:
It's almost a shame. I am genuinely impressed with the gains the team has made in both, language aspects as well as JVM technology. They have some brilliant people working on it and I love to hear their talks (Brian Goetz and Mark Reinhold, mostly).
But I suppose I would say the same about .Net, it's just that you guys have much less public exposure of your internal reasoning.
I've seen the gains in Java; the main things that would close the gap are not yet there in Java. .NET code, especially when tuned, still has significantly more knobs in your code to tune and make faster. An example would be proper generics with value types together means less boxing in generic code in general overall but there's a lot more I can think of. I've seen almost 50% of gains, particuarly when doing math like code, of moving away from Java to .NET especially if the jump to C/C++/Rust is too much for the team in question due to other requirements.
1. The overall architecture (with the JVM) made it slower than the equivalent C# code.
2. C# really started embracing modern language features at a time when Java was kind of languishing (lambda functions, async patterns). Java seems like it's been in perpetual catch-up since then.
(Not OP, disclaimer, I work for Microsoft and this is only my opinion).