4.2 with SqueakVM vs 4.4 with Cog on a 1.6GHz Pentium-M, 2MB L2 cache, Ubuntu 12.04.2:
239,700,374 bytecodes/sec; 8,259,068 sends/sec squeakvm 321,608,040 bytecodes/sec; 43,371,304 sends/sec cog
4.3 with SqueakVM (the all-in-one image on the website) vs 4.4 with Cog on a 2.4GHz Core 2 Duo, 3 MB L2 cache, OS X 10.8.2:
527,291,452 bytecodes/sec; 11,599,578 sends/sec squeakvm 652,229,299 bytecodes/sec; 74,030,622 sends/sec cog
In other news, I've updated my MemoryUsage class to work with 4.4, and restored the older versions from a backup of the website.