Hi Craig,
Yes, we did a Great Plains conversion to Adagio 2 years ago in the Waterloo region (for references), and we're in Waterloo too. Usually, we would be doing from Dynamics to Adagio but some older GPS sites are still out there without software maintenance, but are doable with proper planning.

Our conversion process, converts open transactions and transaction history. We test and can convert your data "on the fly", and once you are on Adagio, you can take your Great Plains to the curb. :))

Give us a shout if you want to meet and talk about. And/or Doug's group is also qualified and capable to provide assistance.

Thanks,
Brian