I haven't had vacuum to my transmission for about 6 months since my modulator failed ('81 TD). Yea, it shifts hard, especially the downshifts, but I don't worry about it too much since hard shifts are actually easier on the bands. Of course, it is hard on the drivetrain, but I have learned to put it in neutral for the 3 to 2 and 2 to 1 downshifts until it warms up. Once warmed up, they are just crisp.

I am waiting for the time to replace the modulator and the K1 spring. I'll probably adjust to crisper shifts, since my tranny has 260k and I want to extend its life as long as I can.