All three phones feature the same dual-core (28nm Krait + Adreno 225) Qualcomm MSM8960 SoC running at 1.5GHz, and 1GB of memory. Software isn't final on either of the RAZR HD devices so we'll hold off on doing any real performance analysis there. We should have a final RAZR M later today so we'll update with a quick look at performance there.
NAND storage ranges from 8GB on the M, to 16GB on the HD and 32GB on the HD MAXX. Additional storage expansion via microSD is offered on all three models.
Battery capacity varies between the three as well. The M comes with a 2000mAh battery, the HD bumps that up to 2530mAh, and the HD MAXX features a whopping 3300mAh battery just like its predecessor.