i have 04 v6 approx 53000 miles with the same problem. the question is, do i HAVE TO replace valve body? if i don't replace the valve body to save a few thousand $$$ now, will it cause more serious problem down the line? if valve body replacement is just to get rid of this annoying jerking/sudden shift then maybe i'm with alpha60, i'll just avoid it by switching into manual gear.
It's up to you if you always want to manually shift your transmission... If anything, It may get annoying, and even if you forget to put it in Manual mode, and it Bangs down a gear, it's not very good for the driveline... We all know that Banging sound, and its pretty violent... I think it's almost the same as reving it up in Neutral, and then slamming it into gear while revved up
I don't see any reason for you to keep shifting manually to help buy time before you fix the actual problem?