Cool! I've got both and consider Katz a better writer of English. His prose is just more enjoyable to read and flows much better than P&V's rather too literal translations
I read his translation of Crime and Punishment and I liked it a lot, I saw he had a new-ish translation of The Brothers Karamazov but I haven't read that yet.
Personally I'd highly recommend reading Michael R. Katz's translation of The Brothers Karamazov instead.