I'm not using an active crossover (so am basically just connecting a separate 100W amplifier channel to each set of bindings before the speakers' internal crossover), and actually only biamped my 7NTs as an experiment because I have two spare channels - theoretically I didn't expect it to make any difference.

It turned out I could actually hear an improvement (mostly a less strained treble to my ear) so I kept it. I suppose my real question is whether going from 100W to 200W feeds into my N803s would make a noticeable difference, or whether to have a real improvement I'd need to move to a totally different amplifier line (e.g. Rotel, B&K, Musical Fidelity etc.).