Ha, looks like it's a tough one! Here's how I see it:
I like that Phyrexian Reclamation can be slotted in decks with few creatures as long as you have the right targets. But having to pay two mana and two life is a lot so I'm not sure you can actually build those "slow value decks". I also wonder if Cemetery can become a no-brainer and simply have you repeat things over and over.
By the way, it's incredible how many good, interesting cards are there in Urza Block. It's not just the well-known busted cards that are powerful, it's everything.