real rowcount is returned, meaning a query such as
query(func.count(A.name)).count() will return a value of
one, since that query would return one row.
+ - Lots of performance tuning. A rough guesstimate
+ over various ORM operations places it 10% faster
+ over 0.5.0rc3, 25-30% over 0.4.8.
- bugfixes and behavioral changes