K8000, heh heh.
we got a deluxe Ridge Racer with a 33" RCA tube and K8000. had the game in storage for all of 2009 and half of 2010. one day I gathered up enough nerve to resurrect it and noticed that the brightness would vary on it. I figured it was also due for a cap kit, so I did caps and a flyback on it.
EVERY. SINGLE. SOLDER PAD. where the flyback goes got burned off. I had to do a number of hacks, but got it to work. the cap kit is no picnic, cause there's no standard kit that comes with a sheet of cap locations/values... you have to figure this all out on your own.
about a little more than a year after I did all that work on it, the monitor had a blank picture. I could still hear it turn on, but it was like the heater circuit took a shit on it. so I had to pull the chassis and inspected everything on it and found like a big blue resistor or something where the solder pads, also, burned off. so I reworked a lot of shit on it to get it up again, but was successful.
I'd probably do the 5515, I've had sufficient luck with the U5000s I've got, and I have a K7500 that's just got a shitty tube, that's about the only drawback to those is the tubes. K8000 is just a major pain in the ass. its design was to make it easier to replace faulty components (hence the separate deflection and power supply boards) but it just introduced a lot of unnecessary variables into the equation. and I'm glad I finally know why those things need two isos, lol, 120 and 30V!