Can someone clarify this for me?
On the carbide web site under HDZ there is 4 type
Upgrade from XXL belt drive
Upgrade from XL belt drive
Upgrade from Standard belt drive
Upgrade from Z-plus
XL and standard is out of stock, I am wondering does selecting the XXL belt drive will be that much of a difference for those who own the XL or Standard SO3 belt drive?
On some of the upgrades you reuse some of the existing hardware like the X motor from the belt Z. On the HDZ you reuse the Z motor from belt drive Z but on a Z-Plus you get a new Z motor. So if your machine came with a Z-Plus you have no Z motor to put on the HDZ because the Z-Plus Z motor is incomparable with the HDZ. So you could read through the upgrade instructions to see if you have the required hardware to successfully upgrade to HDZ.
I upgraded to HDZ on a Shapeoko XXL about 1.5 years ago and I love it. I recently upgraded an XL to Z-Plus. Frankly I wish I had upgraded to the HDZ. The Z-plus is ok but it is not as good in my opinion as an HDZ. My HDZ was a version 3.2. I understand the newest version is 4.0. I have not seen what they did to make the different versions or how to differentiate the various versions of HDZ.
If you have a Z-Plus you already have proximity switches. Some of the kits may not have the mounting hardware for the Prox switches. In my XL case I upgraded to prox switches at the same time as the Z-Plus but a Z-plus is not comparable with mechanical switches, the HDZ is.