Actually, I think there was.
With a voltage regulator in there, as you've switched to, when the signal pins are high (2.85 - 5V) there will be some current flow from the signal pin through the 110 ohm resistor to the regulated voltage area, damping ringing on the high end.
Under your previous configuration, when the signal was high, there could be no current flow to damp the ringing because the diodes acting as the voltage regulator would be reverse biased. Using diodes as a voltage regulator only works if the current flow is always in the same direction and if the difference in voltage between the ends is large enough to forward bias the diodes. Neither of these conditions are always met in this application.
I have not given full consideration to how the capacitor may have contributed to the termination, though, hence my earlier request for an explanation of how it was meant to work. It's possible I've overlooked an aspect which would make it work. But based on what I know so far, I really don't think it should work properly -- using a real voltage regulator is a much more robust solution.
Of course, in many instances, even no termination will still allow a SCSI bus to operate, so the fact that some systems with the old style terminators work is not proof that they're doing their job properly.
Anyway, all that said, I think it's great that you're moving to using a real voltage regulator circuit. Nice work.