Best I can recall, the big delta is that Soundlabs have much more energy from 100hz on down than any Apogee I've heard - including the big full range ribbon units and the "Slant" hybrid models. (I never heard the monsters with separate subwoofer cabinets.) On that basis, I'd prefer the S-L, although the fairer comparison may be to the Apogees I haven't heard. Disclaimer: there was a looooong gap between my auditioning Apogee and Soundlab so this is definitely FWIW.
Marty
Marty