Jeff Victor has a interesting entry on his blog regarding performance of zone patching with soon to be released parallel patching and SSDs compared to serial patching and spinning rust. It's nice to finally see a near time solution to this since it has been a problem for quite a while.
In short he was able to speed up the patching of 16 zones five times with SSDs and parallel patching and 3 times with HDDs and parallel patching:
Talks I have given
2 weeks ago