Using LZO/Zlib compression led to the performance being degraded when dealing with multi-threaded random writes of large files.
With the AIO-Stress we have a test where using compression leads to better performance, but where the LZO compression performance falls behind Zlib.
Overall, using transparent LZO compression with Btrfs is faster than Gzip for most scenarios, but there is also slightly higher CPU usage in using this algorithm (another article will look at the file-system CPU usage). Be forewarned, if enabling LZO compression, you may then run into problems if trying to mount the Btrfs file-system on a pre-2.6.38 kernel.
These test results are also available on OpenBenchmarking.org.