So the ball hop is caused by the distance between the end of the inlane and flipper? Would a larger diameter inlane guide help? I'm wondering if a machine shop could reproduce the inlane guides a little wider up to the ends, which would have to remain the same diameter to go through the playfield.

I've switched to superbands and they're slightly thinner than traditional flipper rubber, eliminating the hop.

You might also want to try to adjust the flipper bats / rods themselves, there might be more 'give' or play in them than the ball guides.

Get a new set of flipper frames from Cliffy.

http://www.passionforpinball.com/FlipFrames.htm

Didnt see the part about the wire only guide. Make sure the wires aren't bent, make sure they are not sitting too low in the playfield. You want them to be in the center of the ball when its rolling. Too high or low will cause hop.

I had no ball hop on my taxi after adjusting the wireform, but it sounds like you got it covered. - good luck!

The hop is real. I've got it too on the right flipper only, and its definitely caused by the gap between the rubber and the wire. I tried bending the wire, and that did help a bit, but it by no means fixed the problem.

I tried superbands as well, but it was hit or miss. If the ball was moving fast, there was a seamless transition...but there is with regular rubber when the ball is fast, too. I removed the superbands because it made the flippers so strong the ball would brick against the ramp curves and dribble down.

...would it be possible to convert Taxi to use other inlane guides? You'd have to drill holes and it would be sad 'n all...but is it possible with off-the-shelf parts?

I'm looking at the pic you took and trying to think of a solution. Can you take another pic like the last one but with the flipper in the up position? I'd like to see if it gets closer to the guide. I wonder if you could do something similar to the ones on Judge Dredd.