Jeremy,

regardless of how you change the fluid, i would definitely change the filter, like maybe daily for a few days. when i was doing some research, the places that offered tranny flushes did NOT change the filter because in their view it was unnecessary. if the theory is that new fluid can loosen crap in the tranny, i definitely would install a new filter and pray that it catches said crap before it does any damage. this may sound extreme, but the price for a reman or used tranny plus shipping is extreme.

also, i would not do the top off thing because (a) it would suck to have to top it off on a regular basis for an indefinite period of time and (b) being out it the sticks not knowing when your tranny might go sucks. good luck!