We do FloralSource. We're in a 6 month trial period right now (free), and so far it's going ok.
We are not getting many orders, but the orders we do get are moneymakers. Just not sure if the low volume is going to make it worth our while.
They call and confirm that you can fill an order before they send it to you, which is 'ok', but can be bothersome during busy periods.
One huge thing I don't like about them (found this out after we accepted the free trial), cheapflowers.com is FloralSource. Yuk.