No in depth review just yet, but I have signed up, added the code, and look forward to seeing what the new service has to offer... Have also (in response to a helpful comment from David) moved my sitemeter stamp so that it is on every page again. Maybe now the exit stats will be a bit more interesting?
I added the new Performancing Metrics yesterday and can say that while I won't be throwing my SiteMeter away, it is quite convenient to have what looks to be an accurate record of individual post popularity. I would think that would be a great feature for you as well since you have many posts in the archives, like all of the Blogger hacks, that continue to attract traffic.