In case you didn't notice...
Although the description is somewhat vague, the improvement in audio clarity is quite remarkable. The feedback I have had so far has been overwhelmingly positive and I would strongly suggest upgrading your radio to this release if possible.
As far as I am aware, these enhancements are not available in the first generation MOTOTRBO radios (DP/DM3000 series).
If your radios are using a very old firmware version, upgrading to R2.5 will also get you access to the enhancements made in R2.4 as well as give you the opportunity to buy SINC+.