[pragmatic]

2 things:

1): Most projects that I've used c# for just aren't performance constrained. What's more important for us is the productivity dimension. We have _lots_ of hardware. We have a few programmers.

I've actually just finished the _only_ c# program that had a performance aspect. It was/is an in-house search engine. I profiled it, fixed the hotspots and it's fast enough.

2: MSFT Marketing. Linq|dynamic are heavily sold by Microsoft. You'll have to read Joe Duffy's blog for actual performance advice: http://www.bluebytesoftware.com/blog/2010/09/06/ThePremature...