snorthway, R25.0 software does not support the Legacy P12 APs. Those should not be upgraded beyond 24.2.2. See the 24.2.2 or the 25.0 release notes for text on this. You can upgrade all the other platforms - the P11 SMs, 450i, 450m, 450b, etc, but not the P12 Legacy APs. Anthonyw is correct in that most of the improvements in R25.0 are on the 450v platforms. But there are a few improvements on the other platforms, and support/debug is generally easier when operators are on the newer software