Solid performer

Here comes my subjective impressions after spending weekend with Olympus M.Zuiko Digital ED 40-150mm F2.8 Pro on OMD E-M1, firmware v1.3, lens firmware 1.0.

• very sharp across range, gets little mild at wide end and long tele end;
• beautiful bokeh;
• prone to flares, with clearly pronounced magenta tint even with lens hood extended;
• could be used as, but generally does not substitute portrait lens e.g. M.Zuiko 75mm/1.8;
• focus not as fast as M.Zuiko 12-40/2.8, but OK (elements move longer distances). Center weighted metering contributed to slower focus speeds;
• solid choice for street/documentary work, wildlife, maybe sports and everywhere where longer reach is needed;
• solid build, truly professional feel;
• lens hood retracted contributes to "fat"/"big"/"voluminous" image of this lens. Hood can be taken off, lens becomes more "slim". However you need it on sunny days to avoid flares;
• it's pretty inconvenient to zoom with lens hood retracted, especially with tripod collar getting in your way. Extend hood or take it off.
• tripod collar is not convenient if you carry camera around and can/should be taken off because you'll really notice weight difference without it;
• you will surely need grip for E-M1 with this lens, otherwise it becomes too difficult to hold camera with long lens in the long run.

Final mark for this lens - if I gave 12-40/2.8 5 stars, then 40-150/2.8 would get 4. Solid performer, but not so spectacular as 12-40.