K Mount to MFT Adapter Advice

My pops gave me a bunch of his old Pentax Lenses. They seem to be in great shape. I've prices all over the map for K to MFT adapters. From as little as $50 to a few hundred. Anyone have real life experience using K mounts on MFT camera mounts?

Besides focal length and crop factor are there any other gotchas or things to be aware of when using K mount lenses on MFT mounts?

I look forward to your input.

Than you Mike Kroesen