Please don't take this as any sort of put-down, but I definitely wouldn't regard the Pentax K-30 as "decent pro-sumer". It's an entry level DSLR. There's absolutely nothing wrong with that - some really excellent photographers use similar equipment and get amazing results - but it's not really what I was writing about. I also note that your m4/3 camera appears to cost almost double what your DSLR does despite having a smaller sensor (which is my far the most expensive part in any camera body), so it's not surprising it has rather more features.

The cameras I was really talking about are professional and semi professional tools - which right now is cameras like the canon 1dx II, nikon d5 (pro) and canon 5d III, nikon d810 (semi-pro). Pentax, I'm afraid, doesn't really have anything comparable right now.
The control systems of these bodies are very, very different to what you're used to - the learning curve is far steeper, they're less forgiving of mistakes, but in good hands are remarkably effective tools. They also cost rather more - between USD $2700 and $6500 for the body alone.

Holding the release down and choosing the best image of the set is a common way to capture images - as I explained however, if there's a specific moment you want to capture you're very unlikely to get it this way. If you're taking a series of shots of something moving and you just want the best one? Well then buffer size becomes at least as important, if not more so, than framerate. It doesn't really help if you capture 11fps but can only do so for one second when the person next to you can do 9fps for 20 seconds. I'd also note that many users of high-end DSLRs have spent this money partly because they are indeed able to get that single perfect shot, due to lots and lots of practice.

You're absolutely correct about mirror induced vibration being a real problem for some shots. Electronic first curtain shutters are actually present in some highend DSLRs (the nikon d810 for example) - but as you say, mirrorless systems tend to be excellent at landscape photography (although sadly tilt/shift lenses for mirrorless cameras are few and far between). The point I was attempt to make was that DSLRs are masters of flexibility - m4/3 cameras do some things exceedingly well, and some things not quite well. DSLRs tend to be good at pretty much everything, if you can live with the size, weight and cost. A great deal of professionals have both - mirrorless systems for the times when they work well, and a DSLR for everything else.

P.s. in response to your paragraph on wingtip focus I've a couple of points. Firstly, touchscreen focus is great for many things, but it REALLY is not going to help you capture a fast moving bird in flight. Secondly, the head and the wings are both moving, in multiple directions at once. Neither are differently "sharp" to the autofocus sensor. The reason wingtip focus is such an incredibly common error with birds in flight photography is because the wingtip is closer, depending on the angle may sometimes move in front of the head, has more contrast and tends to be bigger (depending on the species). All these factors combine, and thus why it's a very common issue. Note that you'll only see it if you have a pretty shallow depth of field - which you're less likely to have on a small sensor camera, or with a slow lens.