Film & Digital lenses

I was a CMOS-C sensor lover, first a D300s, then a D90 which has
less noise in the sensor (later version?) and thrilled with the size
and capability of the DX lenses for years.

Then borrowed a full frame FX two years ago and saw the difference
a full frame sensor does make. The full frame bodies and lenses are
bigger & heavier needing larger carry bags & tripod if that is an issue.
The 'closet queen' film lenses that are smaller than digital and work ok
are hard for me to focus with old eyes since the split focus window
is no longer available as the easiest focus option (which worked well
even in dim light).

The full frame high end digital lenses are probably better at resolving
now than many older film lenses since they are designed for sensors
that exceed the limits of film above around 20mp.

If you are not making huge prints or enlarging detail via extensive cropping
the smaller sensor and lenses work just fine for most people.