I'm definitely an old-school code-sql-by-hand guy and I used an ORM (Entity Framework 4.0 Code-First) for the first time for my startup project, a data-intensive online strategy game.

I've found that for many things, it's so much faster in terms of dev time, especially with the super-cool code-first approach, to get things out there and working using the ORM. I can create a new fully-functioning and reliably-working repository class, along with its test double, in around a minute. Really.

Of course, I have found that I've had to replace bits of it with hand-coded SQL for performance reasons. But I've decided to stick this general approach for now because I don't need to substantially rearchitect everything, I can just replace the very few bits that have proven to be an actual performance bottleneck, and keep the development speed for the many places where runtime speed just doesn't matter as much.