I wish the In-Body Stabilization would work without half-pressing the shutter button; this way I can have IS on while in magnified view, to help fine tune focus. As it is, as soon as you half-press the shutter, the magnify feature is deactivated.
I am quite pleased with the E-M5 and Minolta 250mm combo. Imagine shooting 500mm (35mm equivalent) without tripod. That's what I call freedom. There are many opportunities with a longer lens, which allows the capture of some candid moments that could otherwise not available.
All pictures below were taken with the Minolta Rokkor-X RF 250mm f5.6 mirror lens and Olympus E-M5.