Personally, having owned a SL1 and an LS300,  (long story, both of
them bought new), I'd run as far away from the Saturn as possible.

IMHO, there's no way your Saturn will outlast that Sentra.  I,
personally, will never own another Saturn for as long as I live.

The build quality is, well, like every other GM vehicle.  Runs fine
until the warranty runs out.  Not to mention the irritating wind noise
from the complete and utter poor design of the door seals.

And the LS300 was even worse.  Do you know that you have to
practically take the entire top of the engine off just to replace the
thermostat?  $20 for the t-stat, $600 for labor!

Good lord what a flaming piece of crap that car was.

So now we own three Lexi (an LS430, an ES300 and a GS300) as well
as the Sentra.  All four cars have never given us a moments worth of
trouble and the GS300 is a 94 with 177k!  The fit and finish of that
car is like a car only a couple years old.  You can't get that in any
American car I know.

If the transmission fluid is clean and doesn't smell burnt, it's
probably OK. It amazing how many "well maintained" cars never had the
trans serviced.