I can consider myself long time Pentax user, I guess. Only use Pentax cameras and lenses.
Currently using a K5 and K5IIs.
I love the ergonomics or Pentax, and the solid feel when you holding on. When Canon and Nikon have the 6D and D600, I think I can finally afford a FF!
tried them, not impressed.... plastic feel, bad placement of buttons, and just not feeling it like Pentax. I hesitated.
Then came the A7, A7R. I would love to have the A7R. but at the same time I am worry about the ergonomic, the EVF lag, the focus speed, etc.
Today I went to a camera store to try it out, they only have A7, and they only have APSC lens to try on...
But! the hands on remove my doubt about EVF! it is much much faster than I imagine it would be. Very very usable I would say. Focus is fast, at least for a person who used to Pentax focus system.... the camera feels very solid, and ergonomic is much better than I think! after a while it feels good in your hand. The placement of the wheels are definitely odd, and I think the menu button could be placed better. They only have the 10-18 apsc lens for me to try. The menu system, is also pretty close to how Pentax implement the menu system. I can easily find where things are. I end up thinking, the EVF is really impressive, and this is definitely a camera that can 'replace' my Pentax. OK, the shutter is a bit loud, but when I first got my K200, I think the loud shutter is actually pretty cool.
Also, that damn menu color on A7 make it look like it is a touch screen and I keep wanting to touch the screen to make changes. lol.
Now, before I left, I am excited to hear the manager telling his employee features about K-3, so I ask them if I they have K-3, they did!
As soon as I grab the K-3, it felt so heavy compare to the A7! and the handle is definitely bigger than K5 (too big for my hand), but some will like it I am sure. Then I play around with it..... man! I can't change setting efficiently on the K-3, they have changed so much (or is it because I have spend close to an hour on the A7?) from K-5!! This is so strange.. I felt embarrass to not able to change the setting quickly as a long time Pentax user!
I will go back to the store to try A7R to get a feel of shutter, fps, and AF on that one, when they have one in stock. I left the store feeling the A7 completely change my view towards mirrorless camera and EVF. They are, in fact, very usable.
If you haven't try a mirrorless before, the A7 will change your view. Give it a try.
I am afraid, the EVF is probably where we will be heading in the future... just sharing my experience.