Important to keep current with the latest firmware releases?

I upgraded to 5.2.5 6/09.  I recall having to perform incremental upgrades through a couple versions to get current.

I notice that since then there has been 5.3.6 and now 5.2.10

http://www.cisco.com/en/US/docs/voice_ip_comm/csbpvga/spa2102/release/notes/spa2102_rn_v5-2-10.pdf

Not having any issues referenced within the above 5.2.10 pdf (or any noticeable issues) & can't find release notes on previous versions.

Should I keep current with version releases and must we perform incremental upgrades from 5.2.5 to 5.2.10 ?