Well, on the stage, it may sound odd because "my" side has the primary distorted tone, and the bass player would hear the rawer tone. For leads, on his side, it may sound thinner...
But in the mains up front, if mixed properly, it sounds huge, more in the sense of thickness and full frequency response. PS - I was the only guitar player when I played semi pro.
I personally used to use an ADA MP-1 preamp with a Mesa Simulcast power amp on my side (with 2 Marshall speakers), and then a Marshall 900 on the other side (with 2 Marshall speakers).
I would run guitar ->wah->chorus (split the signal)-> one side goes to ADA, the other goes to a TS-10, then the Marshall. The ADA was the effected tone, and the Marshall was bone dry (minus the use of the distortion pedal here and there).
You could easily accomplish this same type rig with the use of two combo amps. At home now, I have a JSX combo with my "VH" type tone, and I also have a Marshall Valvestate 20W amp that I sometimes run in unison. I have the Marshall on a totally clean channel, and run a slight distortion using my TS10. The volume of this amp if about 3/4 of the JSX, but you can tell it is there. Many pro guitar players run a similar rig to get the fullness of a cleaner amp with the balls of a distorted one. Get a good sound man to mix the two, and you will have a tone to die for.
Another way to think of this - imagine two guitar players in a band; one plays the heavier tone (think Slash), the other cleaner (think Izzy). The constraint here of course is that your the only player (no inversions or melodies), but the tonality may be similar.