Hey - we primairly use FundraiseUp and leverage Stripe on the back-end as the actual CC processor. FrundraiseUp allows for a parent/child setup which makes admininstration pretty easy and allows for a unique instance of Stripe to be linked to each Child Account (or you can link everything to one stripe, depends on how you run your bank accounts).
I think its pretty great system and my projects seem to like it. I will say that they really provide a TON of data and options which although great can be a bit of overkill for projects who just want something simple. It is easy but you have to know where to click to make it easy so you dont get lost in all of the customizations you can make.
Prevously we used Network For Good and it was okay... but I would not recommend it.