I have/had all three of them

At one point in time I put Emimence DeltaLite 2512II speakers into my GS112s.
And that's almost exactly how the SL112s sound (the SL112 has customized 2512II as well): GS112 with a much better mid articulation and more highs than the db112.
To my ears, the SL112 lies RIGHT in the middle between the db and the GS