great to hear, I've been meaning to use Spreedly/core almost a year now, but didn't take the payment step yet.
It would be interesting if subscriptions were also in Spreedly Core, but I can't imagine how it would work, I guess spreedly core could ping the servers of the customer if the CC failed or expired, but I guess it's unnecessary since an effort is always required in that case, so building the subscription logic on the code seems logical.
I haven't used spreedly core yet, but I really like the team, they always answer emails and help around payment topics, can't wait to solve gateway problems and start using spreedly