I am certain the reasons to upgrade are product support and program updates (if AMB/MyLaps software is being used).

Our local tracks (both carpet and dirt) use the old AMB 20 (no personals). Hopefully it keeps on running. As a club we could not afford to update even with the allowance (which probably does not apply to our old system).

Also if I have read correctly, the older AMB as well as the newer personals will work with the new system; the MRT is the only one that doesn't.