I have been seriously considering the Olympus m43 system for a while.
Olympus OM-D E-M1 Mirrorless Micro Four Thirds V207010BU040 B&H
^ This $1299 deal is not helping the cause either. Hahaha!
The body alone goes for $1099. The lens alone goes for $999. I'd be saving $799 on this kit. My guess is that it will probably go cheaper or some other incentives will be thrown in this season. I also have a spare car that I'm about to unload & all the profits can be used towards camera gear.
I got to play with my younger brother's Olympus OMD E-M5 Mark II along with the Olympus M.Zuiko Digital ED 14-42mm f/3.5-5.6 II R lens & the Olympus M.Zuiko Digital 25mm f/1.8 lens & I was pretty impressed with the AF performance, 5-axis IBIS, IQ, & compactness of the system. The AF is better than the AF in my K-50 both in tracking & low light. It's not like leaps & bounds better than the K-50's AF abilities, but the E-M5II hunts way less in shooting moving subjects in low light & the focus is more accurate. Then again we are talking about a more expensive & recent "apple" OMD E-M5II body versus a lower end & slightly older "orange" K-50. The IQ is great up to ISO 12800. It falls apart after that, but still usable to ISO 25600. This is where K-50 beats the E-M5II. The K-50 has slightly better looking shots at ISO 25600, but I really never shoot at that ISO. I actually try not to pass ISO 6400 most of the time. For having such a small sensor, the E-M5II is pretty amazing.
I read a few reviews about the E-M5II & the OMD E-M1 & even though the E-M5II has slightly better 5-axis IBIS, it seems like the E-M1 is better overall. Kind of like the K-70 versus the K-3II thing. Then there is the 4.0 firmware for the E-M1 that pretty much improves & adds more features that were previously unavailable in the E-M1. It's like a whole new different camera than what it was in late 2013 & most reviewers haven't re-reviewed it since the firmware's introduction late last year.
So yeah. I'm on the fence as far as joining the m43 camp or staying with Pentax. I love Pentax quite a lot, but I also really love the Olympus m43 system. I can't really afford to keep both of them. I'd would unload all my Pentax gear if I jump ship. That would be my 2 K-50 bodies with their respective accessories, 4 lenses, flash, & the wireless remote. It's not much, but given the performance that I'd get out of the E-M1, it would seem kind of pointless to keep my Pentax gear & would rather use the money towards additional Olympus lenses.
On the other hand, I'm still waiting for info on the upcoming Pentax APS-C flagship. I'm now dead set on getting that versus a K-3II if I stay with Pentax. I'm pretty sure that it's gonna be a pretty awesome camera & the IQ is going to be much better than what I can get out of the Olympus.
But yeah. The ability to go a bit lighter & fit more lenses in my bag along with very good IQ with the Olympus m43 system is kind of tempting. Not to mention that I can share & swap lenses with my younger brother. I also know that I give up something for something else like DOF, high ISO IQ, & related. That's something I can deal with. I'd also be on the "cheap" end of it by getting the OMD E-M1 now when it's about to be phased out by the Mark II & then getting the OMD E-M1 Mark II later on when it's being phased out by the following Olympus m43 flagship. Hmmm........