CodeIgniter vs Kohana: which one to choose?

[eluser]Unknown[/eluser]
I know I know, this is a CI forum so I suppose asking such a question here doesn't make much sense. Thing is, Kohonaphp.com's forums are pretty bleh (quite ugly and inconvenient, and most of all seemingly quite inactive), so I was figuring posting here was the best way to get feedback from users who have tried out both frameworks.

So, I discovered CI about two weeks ago after googling PHP web frameworks for a while. CI was mentioned a lot as a very lightweight, fast, yet featureful and extremely well documented/user-friendly framework, so I gave it a try. It didn't seem nearly as rich as Rails (which I poked around with for a few weeks), but it did feel really nice and, indeed--lightweight and fast.

After playing around with it for a few days, I then heard about Kohana. Kohana is said to be "CI on steroids"--basically the same stuff, but strictly PHP5 and with lots of improvements/additional features here and there. So I gave it a try as well... and really liked it. Pure features-wise, it seemed--indeed--a level above CI. And since I don't need PHP4 compatibility, I ended up figuring it was the ideal framework I was looking for.

Fact is I'm still hesitating a bit, for two major reasons:
1. Kohana seems young. Maybe a bit too young. Most people don't even seem to know about it. Documentation is pretty good but still lacking; community seems small; forums look pretty much inactive. The latest official download package includes a module which is outdated and therefore doesn't even work (Auth). Young indeed...
2. Performance. I need to know if Kohana is as fast as CI (or faster for that matter), but I don't seem to find any decent benchmark out there. I don't really have the time to run some myself--I don't even know how to make proper ones anyway. PHP 5.2 (which is supported by Kohana afaik) is supposed to bring some performance enhancements, but who knows if it's being exploited correctly.

Has anyone run some performance tests (preferably with the most recent versions of the two frameworks) and can give me an idea of which one performs (overally) better, and by how much of a margin? I'm also interested in general comments about what you guys think about Kohana in general, why you haven't switched, etc.

Thanks!