some of pattern should be simplified if we use some heuristic in transformRouteIntoRegex
e.g. before optimalization routes like **.groovy doesn't work at all (or last too long to process), because they were too complicated.
I've just hit this issue while preparing for my GGX talk. The performance of those regular expressions is quite bad and this looks like a high priority issue as most of the requests have to go through routes filter. This should definitelly be fixed before next release. I don't have time to play with it ATM, but this is the first thing on my list for the weekend after GGX.