ActiveMerchant Paypal Pro Support

How is ActiveMerchant's Paypal Pro support? I am migrating a client's
site to Rails that uses Paypal Pro and they have been pretty happy with
it (and know how to use Paypal's website). I tried first setting up
the PayPal plugin directly, but ran into some issues and then I noticed
that ActiveMerchant has PayPal Pro, but its labeled "testing" and
hasn't been updated in 3 months.

I really like the idea of AM because it's so easy to use, and will make
it easy to switch to a different gateway if the need arises.
Unfortunately it seems like there's a lot of talk about ActiveMerchant,
but not much actual use or documentation. I'm excited enough about it
to put some open-source elbow grease behind the PayPal module if need
be. Anyone else using it?