With mirrorless there is no optical viewfinder by definition. You can't switch back and use something which isn't present in the camera.
If it's an optical viewfinder you want, then mirrorless simply isn't for you apart from several compacts which have a viewfinder, albeit not TTL. To me that's a backwards step, been there and tried those years ago, hopefully they're not the future. My old ones are languishing on the shelf unloved! I've no wish to add to that collection.

I am of the opinion that mirrorless cameras take over the process. I can't see why anyone would prefer them!

Trouble with that is, if the image is going directly to a fresnel screen providing for a true viewfinder optical image rather than a video screen, the photographer is expected to be able to time the shot rather than the electronics. The camera's electronics aren't actually able to see the image when the mirror and focussing screen get in the way.
Do you want a camera that takes the photos itself, or do you want to take them? That's the subtle difference.
A real photographer wants complete control over the image and not rely on a hit or miss automatic electronic system that requires delving into a myriad of menus to set it up ready (by which time the intended subject may well have gone away.) I suspect that's why some return to Pentax after not getting the shots they wanted with a totally electronic system.
It can take quite some time to adjust the exposure compensation on many electronic offerings having to hunt for the setting in a menu option (if you can even find it.) Not what you want on a dark, wet , windy evening in a camera without WR.
If anyone's thinking of swapping systems, look long and hard at the method of fully controlling the camera, not just the headline specs!

We've seen quote a few forum members circling round the brands who seem unable to settle on anything. That must be an expensive course to take.

Just to let everyone know this week's weekly competition is now up and running. The theme is Uniforms.

https://www.pentaxuser.com/competitions/weekly--589---uniforms-821

Absolutely.
I think Pentax were testing the water for mirrorless with the K-01 and it didn't prove particularly popular. So no doubt once bitten, twice shy.

Thanks for that. Got there after a few more attempts!

Have done that now. Thanks John.

Have actually attempted to sign up to ePHOTOzine, however their captcha system is broken.
This is what I get... impossible to get past this stage.



What's that about? I'm guessing they don't want people to join!

Edit: Yet another attempt failure:




It seems I'm a failure unable to solve a simple question (that make no sense to me) so I'll have to forget it then.

And sorry if my real name contains invalid characters, should I write it in Chinese instead?

Sounds about right. 31 or DFA*50?

Or perhaps they've found a pallet of unsold K1000s and reboxing them as an anniversary product with a free roll of Ektachrome included