Test machine: Pismo PowerBook, temporarily deprived of half of its memory to create a real low-end machine even for our standards, with 400 MHz G3 & 512 MB RAM.

Sunspider 0.9.1
10.0.8: 5644.4ms ±11.0%
10.0.9: 5531.4ms ±8.2%
17.0b1: 5135.3ms ±3.1% (PB G4 1.3 GHz: 2016±1.8%)