My 2012 GMC Acadia is at 105k and I need to replace the front struts and will aim for replacing the rear also. I'd like to go with OEM but I was just wondering if anyone has ever put Monroe struts on their Acadia or should I not stray from AC Delco.

I'd stay with OEM Delco. I think you will find the quality superior to any after market parts.

I replaced my factory shocks at ~155,000 miles with KYB on my Saturn Outlook (same platform etc. as your Acadia), and they are great for over 40,000 miles so far. That said, I just looked at pricing and the ACDelco are less expensive than KYB. They'll be fine.

I've been disappointed with the last few sets of Monroe struts and shocks that I've installed.