In the past the previous operators of Sandtoft before 52nd Street Aviation (New Sandtoft Aviation if I recall), operated from Doncaster as well with two permenantly based aircraft.
I actually found flying from Doncaster excellent, the rates were the same except for the landing fees, and the service was great from ATC. A very easy place to operate from.
The tenants/operator at Sandtoft seem to change hands every few years!