Yes Virginia, there is an Marshmallow 6.0.1 update for the ZenPad S 8.0

[patchs]

Well, it isn't a cakewalk but it's there.
Go to the Asus.com support page for the ZP S 8.0, look for updates, you may have to poke around but it says 6.0.1 update, download it on your PC (1.5 GB file), transfer it to a micro SD card, stick the card in the ZP S 8.0 and it will ask you to update. Follow the instructions.
Voila!
Of course you want to back up your tablet before you start but I had no issues. It actually removes some of the bloatware too.
Good luck and have fun and if something goes wrong, don't blame me. You made the decision, lol.

 

[Cameronj86]

My tablet is easily performing better than it ever has thanks to the update. Previously it had a lot more lag than I cared to admit and I think a part of me thought it wasn't that good of a purchase. With Marshmallow, it is a completely new tablet and a much smoother experience overall

 

[muiriddin]

This is a really nice and after this long of a delay unexpected gesture by Asus. My Z580CA is humming along quite happily in Marshmallow after a LONG delay!

 

[nah40]

Did it.
Works far better.
The only problem was it would not connect to my computer, restarting with it connected solved that.

 

[trampas68]

I had trouble connecting to my PC after the Marshmallow update. It was solved by going into developer options and 'Select USB Configuration' and setting it to MTP (it was on charging only). I have had to repeat this sometimes but it now works fine.

 

[Matron]

I updated my Zenpad as soon as I saw this update, and unfortunately, it's turned mine glitchy and sluggish. I only had problems with the tumblr app before updating, everything else worked perfectly, but now, I have several problems. It's sluggish, as I mentioned, and ALL of the keyboard apps I try don't work properly. Swiftkey frequently predicts on every letter of a word BUT the first letter, making that part useless, and then it capitalizes Every Single Word. Again, making it useless. I switch to the stock ZenUi keyboard, or the Google Keyboard, and get no predictions at all. I know, it's silly to be so dependent on such a thing as predictive text, but it does make things so much easier!

I'm thinking of just resetting the tablet altogether, but I'm not sure what the best method to go with would be? I don't know what the difference is between the Factory Reset option in settings is, as opposed to the one you get to through the bootloader.