I wish we had test-driven the V6 when we bought our Camry; but we wanted the stripper loss-leader precisely because of the manual transmission. I got to try the loaner I4/auto later and didn't care for it--it was always shifting, with any adjustment of the throttle. Drove me nuts. Today I wonder if it was because of the "learning" they put into cars these days.
Regardless, the 2.5 with manual is pretty decent. Torquey motor. The six speed is a joke; I find it has a lot of driveline lash and the difference between 5&6 is neglible. That said, we rarely have to downshift once we hit 60mph or so, and that's on NH roads--never really feel wanting on the highway.
I will say if I put my foot into it, it doesn't feel fast--lots of revs, little action. But it's a Camry, we bought it to put lots of miles onto. I can't imagine the V6 being cheaper over the long run. I seem to only manage 28mpg in it, cruising at 75+. Big trunk, lots of space in the back for the kids.