I had one Harley Davidson dealer use them. There is an interface card that goes in the Spectralink cabinet.They emulate an M7310. It was very dicey, calls dropping, MWI lights not functioning. It wasn't eveyone, but it was the people who used it the most. It was an MICS 5.0. Spectralink s/w level unknown.
Hopefully they're better aquainted now.
Adversity is Opportunity