I’m planning on buying/building a new computer and I think I will install Ubuntu 10.10 on it.  My plan is to use btrfs for the first time.  Risky, but I will be taking nightly backups.  However, Ubuntu 10.10 is planning on shipping with the Linux 2.6.35 which has a severe btrfs performance regression as documented here:

• Btrfs Did Regress Hard In The Linux 2.6.35 Kernel
• maverick btrfs slow install

But besides that I’m also hoping that the I/O performance situation will be improved.  It has been very difficult to track down where the bug is but I have certainly experienced it.  I haven’t tested the patches but if they work I hope they find there way into Ubuntu 10.10

• Fix “system goes unresponsive under memory pressure and lots of
  dirty/writeback pages” bug.
• Large I/O operations result in poor interactive performance and high iowait times
• The Linux Desktop Responsiveness Patches Are Feeling Good
• Heavy Disk I/O harms desktop responsiveness
• Very poor desktop response (high latency) during I/O-load with SATA+NCQ