oh and btw, IMO an improvement in shift quality is a firmer quicker shift. This means less clutch wear and longer life. If I can afford it this year, one or both of my 2004R's will be getting shift kits to improve the shift quality and make them last longer.
USUALLY, a smooth shift means less service life out of your transmission. So you better enjoy that smooth feeling shift cause your going to pay for it. lol.
My 304K mile Caprice had the smoothest shifts ever right before the trans finally packed it in. The low fluid was the biggest issue, but I'm sure it was already getting pretty worn. Also my friends AOD in his 89 Crown Vic had very very smooth unnoticeable shifts right before it lost 3rd and 4th gear and started shuddering like crazy. The fluid also went black in a very short period. My experience goes further than this, but just wanted to give you guys some examples.
Heat is what kills a tranny, so being low on fluid makes sense.
I am asking about the engine oil NOT the transmission oil. I mentioned that on the third post.