zfs recordsize - any experimental findings?

[noprobs]

Does anyone have any experience/benchmarks from experimenting with a recordsize other than the default 128K value?

I was going to do some experiments (test environment) changing recordsize value and seeing impact on DeDupe ratios, performance etc, but if it has already been done then there would be little point. This would be for storage supporting a Xenserver host - general ZFS documentation that I read recommended an 8K recordsize for virtualised environments.

NB. I realise that reducing recordsize will increase DeDupe RAM requirements as well as increasing disk I/O..

Thanks,