Performance is way up again, beating CPython on half of the tests:

"Transaction",                mysql
"Add 3000 Objects",              8259
"Update 3000 Objects",           9454
"Read 3000 Warm Objects",        5460
"Read 3000 Cold Objects",        5454
"Read 3000 Hot Objects",        24943
"Read 3000 Steamin' Objects", 1099616

Still needs some GC work to get all the ZODB tests to pass like they do under zopefoundation/persistent#20