In terms of available parameters and flexibility, you will get access to a lot more with the Finalizer 96K ie. the crossover frequencies, limiter attack and release times where these are fixed to the Target parameter in the UnitY´s Finalizer DC.
Features in the Finalizer 96K like mono dithering, normalizer (gain before compression), parametric EQ are more or less features that you already have in the 02R.
Additional features in the Finalizer 96K that you don't have in the 02R are ie. full samplerate conversion (any rate in - any rate out), 96 kHz sample rate support, 3 band spectral enhancement, dynamic EQ, digital radiance generator etc.
The UnitYs Finalizer DC is inside the 02R and presets stored can be recalled by Scene Memory and the eight major parameters (on the faders) can be automated by the 02R's automation.
The Finalizer DC can be inserted in the stereo bus (Extended Routing*) in front of the 02Rs stereo fader for (pre-)mastering. You can also route BUS5.6, BUS7.8, AUX1.2, AUX5.6 or AUX7.8 to the Finalizer input and return these busses via input channels.
Basically the UnitY card routing is determined by the 02R and thus, you cannot use the Finalizer DC as insert compressor on the channels. With a optional UnitY I/O card you get a few more features. In Extended Routing* mode you will have six additional digital outputs (within the available outs on the 02R) and two digital stereo inputs which can be fed directly to the stereo LR bus.
The compression algorithm in both Finalizers are basically the same. But you have access to more parameters on the Finalizer 96K which offers greater flexibility and 'tweakability'.
* note: If a Yamaha Cascade card (CD8-CS card) is inserted you cannot enable Extended Routing and thus make inserts in the stereo bus nor return directly to StLR.