[OM] OM zoom advice needed

[William Clark]

Hey all

        I have the 35-70 3.6 zoom, which I really do not use all that much.
I was thinking of getting the f4 to replace it from a local shop and pocket
the change from selling thr 3.6.  I know there are also 3.5-4.5 and 3.5-4.8
zooms.  Does anyone know of the quality of the non-3.6 zooms or what I
should think about doing?

Thanks in advance....

-Bill