I haven't had a chance really to play around with my tt 801, but here are some observations.
1. The tt 801 DOES have the stepped pitch control like the tt 101. The control panel and speed indication is different though. Instead of showing the actual change in speed like the 101, the tt 801 displays '33/45 +/- .n' where 'n' refers to the number of steps up or down away from 33/45. Additionally, the 801 incorporates a reset buttton to quickly return to 'normal'.
2. The platters are different. The tt 101 platter weighs 1636g and the tt 801 weighs 2706g. The tt 101's platter is damped by a rubber ring seated (glued) underneath, while the 801's platter incorprates 2 rings that are secured to the aluminum via 6 screws.
3. Perhaps as a consequence of the heavier platter, the 801's motor has greater torque.
4. Although the 801's platter is heavier, the 101 motor unit is acually heavier. The materials making up the bezel of the two units appear completely different. The 101 is solid underneath the bezel, while the 801 is surprisingly delicate there.
5. My 801 didn't come with a rubber mat so I don't know for sure how the vaccum function works. From what I can see, there are four holes surrounding the spindle that act as ports for the suction. Presumably, the oem mat has matching holes that traverse and direct the vacuum to the outer and inner rims (where one can see in pictures holes drilled through). These latter holes would be the vacuum exit points and hence where one's records would be held down. Presumably, one can use other vacuum units as long as the suction power is roughly equivalent. The problem is how to jerry-rig the mat if one doesn't have one.
How do the two compare sonically? I'm going to find out this weekend.
For anyone interested, some guy is selling a brand new in box tt 801 motor unit on Yahoo japan. For a very reasonable price IMO. There can't be too many of those left in the world. No affiliation.