Originally posted by Rondec Olympus is a company with great history, but they don't make sensors.
Same as Pentax, Nikon, Leica.
Originally posted by Rondec On the bright side, Pentax can buy sensors from anyone (except Canon I suppose) and so they can put the hottest new tech in their cameras
So does Olympus. They have used sensors from Kodak before using the Panasonic ones. And they are now using LiveMOS sensors because those are optimized for fast readout, which makes them more suitable for video use, as well as for use with an EVF. The sensor used in the E-M5 can achieve 120fps, which impacts LiveView fluidity as well as autofocus speed. And in continuous AF, they sample the sensor at 240fps. From my experience with Pentax DSLRs in LiveView mode, they were nowhere close to the performance of Olympus cameras - just read the LiveView section in your Pentax camera manual for all the limitations. It may not be a simple omission that the K-01 is lacking an EVF - they might simply not be able to build an effective one at this time. I'm afraid even the LiveView is inferior and only slightly improved compared to DSLRs.
Sensors are just one thing - that's why you don't buy them separately, but in a camera. It's the ability of the whole package to produce a picture that matters - like the saying goes, a chain is only as strong as its weakest link.