I have a Fender Blues Jr and a Vox AC4C1 and the Vox always sounded very thin with my Tele and my Strat, to the point where I had to use an EQ pedal to get any 'girth' out of the amp. With a distortion pedal I could see how they could sound close to humbuckers, but to me they're more versatile. Now, obviously, his were likely wound differently, but the combination of the P90s and the hollowbody have a BIG sound.
When cranked, they have this bluesy, dirty attitude that I absolutely love- they remind me of Lennon's sound throughout the Get Back special- it's pretty close (it nails that I've Got A Feeling sound).
I know it's almost a cliche, but they really are right in between they're thick like a humbucker but still have the definition of a single-coil when the volume is rolled off. They sound great! I'm a single-coil guy (Telecaster, Stratocaster with 57/62s, Rickenbacker Toasters) but also have a guitar with humbuckers (PAF clones).