Have you run a PCM quick test with a scanner to see if any codes are either set or pending? This is the first step that should be taken, even before a road test.
If the harsh shift is only out of 1st into (presumably) 2nd, then the TSS may be a suspect. If you are getting other bang shifts (2-3, 3-4, or on downshifts) then don't bother - your valve body is worn.
Placing the shifter in 2nd from a stop should mechanically force a 2nd gear only condition....
A scan tool (not a code reader) would be your best friend right about now. It would allow yuo to read sensors in real time and get a better feel for what's going on.
Steve
