So these are the changes in 17.1.8 -

What's new in version 17.1.8 (Rev 8)

• Version 17.1.8 (Rev 8) is the year-end product update for Sage 300 CRE. Install this version to ensure government reporting compliance.
• In US Payroll, ACA employee and dependent compliance details are now completely copied to the next year.

But if you don't need ACA reporting it appears that the W2's run just fine.  We have already done this with W2's and ACA reporting was done by clients insurance company.  The big deal is without the update, if you are reporting ACA via Aatrix the totals don't roll correctly for ACA reporting should you need it. 

Just my 2 cents. I wish that Sage would re-institute YE updates as a small patch.  when you have 100's of 1,000's of customers (that request assistance) it is impossible to get all upgraded  before the end of January.  

So what is the answer to the question first asked? Is the 17.1.8 a full upgrade install or is there a patch somewhere to update from previous 17.x versions?

So what is the answer to the question first asked? Is the 17.1.8 a full upgrade install or is there a patch somewhere to update from previous 17.x versions?

Full install on the server.  Just run the download on the server and it will remove the old version and install the new one.  You run the client install (like adding Sage to a new computer) on the workstations.  It says reinstall but it's very quick so it's actually patching in the background.