PZ85 has Intelligent Frame Creation - which divides opinion on these forums - and Panasonic's 24p Real Cinema mode (though the 80 will play 24fps no problem). Both of most relevance to Blu-ray Disc playback; neither a deal-breaker.
Oh, and the PZ85 also has a digital audio output so you can feed its internal tuner into an audio system (which is of no consequence if you're planning on using the set with an external Sky/Virgin/Freesat box).
I'd buy on price, and try to have a look at both. IMO go for the less expensive of the two.