I'm guessing ok, but there are different types of automatic transmission fluid. Perhaps the dealers replacement is not as good as what was in the car as new.

Have a look in the book and see what the precise specifications are. Then ask the dealer what they use. Don't say say any more and do the web research on the various fluid types.

I've met dealers who bought oil in bulk that was not to the handbook specification. Not saying that has happened here, but I think you need to check.

Generally, assuming nothing pollutes the oil, use will make it thinner as the shear strength will be deminished. So I would expect you 'd notice even if the right oil was used, but this sound a bit more.

Do you think the clue was in the question? Something like ' You can feel the surge in power'. I suspect your mashing your right foot down a little harder than before m8.

Either the wrong fluid has been used or the wrong amount has been added. Some 'boxes need to be hooked up to a computer to set the fluid levels correctly. I wouldn't let a main dealer anywhere near my 'box (oo-er) - only specialist trannie places would get a look in (oh matron).