I've been debating the same and I will go with Witty and give up on MS. My son has been to the weekend playgroup at Witty and he likes it and is familiar with the environment. Also, Witty offers 2 weeks of transition period for PN, which I think will be helpful. By contrast, MS has been pushing back the opening of the Western campus (previously Easter and now May), and it does not have the transition period.