Holy sh*t.
I changed the starter solenoid (new one, same as Leekellerking's) and battery cable (pos from battery to starter solenoid) cleaned and polished (to a shine!) the lugs and battery posts. They'd been cleaned before, but this time I really tore into them until they were quite smooth, then put a shine on just for the hell of it (smoother = more contact surface) and put a light coat of dielectric grease on everything. The posts had gotten torn up pretty badly from something? I wasn't aware of how irregular the mating surface was, so I filed it down a little and then just sanded it until it was smooth.
I changed the battery cable because a while ago, the lug to the battery had broken off, so I was using a copper one that I'd attempted to cold solder, but apparently it didn't work well. I tore the new one off MickeyX's 650 (sorry) and cleaned it thoroughly, attached.
The bike starts very quickly and easily now. With the choke on, warming it up at 2000 rpms, we were reading 14.5v at the lugs. I cranked it up to 4k rpms, and it spiked to 14.8, but then held at 14.5. Same with 5k rpms.
We shut it down so MickeyX could get some riding gear together. At the RR, the black and white wires read 7.2 ohms resistance after the bike had warmed up a bit.
The bike started right up again, with just a real quick touch on the button. MickeyX got the honors of this ride, so she took it down and around again, around the block twice putting her through her paces. Brought the bike in, and the battery read 12.7! Rotor resistance held at 7.2.
When starting it dipped from 11.9 (we had shut it off and had the lights etc on, and the circuit open, hence lower voltage) to 9.6 but went right back up again. (then we revved it a bit and shut it back down, for a final voltage of 12.57 at the battery)
Re-starting when warm it's just slightly slower than the cold start, but still really good, definitely not where I'd worry about whether or not it'd start again.
Wish I could chat more but I have to get some sleep...
I have some riding to do tomorrow!