Probably, its not yet the time of a new battery generation, but if you ever drove Lipo or FePO4, you will never want to use Nimhs anymore.
Maintenance is much easier than with Nimh. Just charge, drive, charge, drive, charge, drive... No more discharche.
I'm very happy with my FePO4...
-faster servo
-100gr less weight
-Just 1 Pack needed (After racing, the pack is as cold as before and can be charged in 15min