I've been looking into AAC-SBR optimizations lately in hopes of getting SBR working on lower speed ARM devices. I noticed that FAAD supports the low power SBR mode, which reduces the number of multiplies needed greatly. This would be very useful on older ARMv4 devices with slow multipliers.

But I wonder about the quality hit. Is it worth supporting this mode for DAPs where most people will be expecting reasonable quality? I think most devices I'm interested are fast enough to decode SBR in full quality mode, although with a lot of work.