'07 AT Failure?

I have an '07 Pathfinder with 98k on it.

It's my wife's car so I don't drive it all that often but tonight I was driving it home on a hilly road and noticed two things, one is it doesn't seem to have quite the same power that I remembers and two as the RPM got low in overdrive it tended to shudder before shifting.

A quick google search seems to indicate I might have the dreaded coolant in the AT issue.

I remember when folks first started having issues it was a lot of hard shifting, which this doesn't seem to be doing, but the shudder is very noticeable, the power might be just in my head but that thing was always a pretty zippy car.

So besides coughing up the 70 dollar diagnostic charger for the honor of probably handing over another 3k do I have another other options?

I know there's a local shop that has a good rep, I guess i can call them too.

This is on top of having to do the timing chain tensioners last year. It's also had the gas gauge sending unit issue and the prop shaft issue, lucky those two were 100% covered but the gas tank one had just gone into effect about a month before.

Yuck....

K