What prevented me from using Playframework and going with Lift:
1. Play 1.0 (2.0 too?) used exceptions for flow control. I don't think this works for high traffic web sites.
2. Lift's CSS selector templating is slick, I would not like to go back to PHP/JSP/... style templating.
2.0 doesn't use exceptions for flow control - but out of interest, what do you mean "I don't think this works for high traffic web sites"? 1 exception for a request won't affect performance, right?
Although exceptions have become faster, and you can speed them up (overwrite stack generation code), they are slow mostly due to filling the stack trace. Mostly based on this:
Was not familiar with this method, appreciate the heads up guys. Did some quick micro benchmarks and it looks like I got an 11.5x speedup in some code that was using Exceptions for flow control.
Very nice website.
[update: 2.0 has no more exception work flow]