Should I buy the m.zuiko 40-150mm?

It's up to your preferences, it seems a little soft for my preferences, but if you favour light and versatile it might just fit the bill.

 

I've had the same kind of thoughts, but came in to conclusion that the 14-150 could replace also the 14-42 kit lens and all I would really need 99% of the time would be my 20mm Pana and 14-150 Zuiko. But as mitchins said, it is really up to YOUR preferences and I wouldn't make any rushed decisions about lenses even as "cheap" as 200$.

 

I've looked into this,
I might just buy a 40-150mm. I think the 14-42mm M.Zuiko is not so bad, it's probably better than my old 18-70mm Sony as far as kit lenses go.
I haven't looked into the 40-150mm too much, but from what I've gathered and supposed it's much sharper than the super-zoom. Unlike FF and APS-C M.4/3 resolution is overcome by diffraction at about F5.6, which means a super-zoom like that needs to be stepped down to be sharp but will be limited.
I'm no expert, but the examples of images from that lens aren't spectacular in terms of sharpness, which means birding is a no-no, however family snaps are fine.