I purchased an ASUS G751JY that i used the CRU on after reading up about it on blur busters forums. Many people were able to do this with little to no issues on this specific model. I was able to get one super cheap off eBay compared to the almost $2k 120hz Alienware models at the time. The default hz that came on these specific laptops was 75hz (included GSYNC as well), but i was able to OC it to 100hz and it was stable the 2 years i owned it. Once i sold it, i walked through the new owner on how to set it up and as far as i know he still has it running @ 100hz another 2 years later.
I would take the time to research the model you want to try it on beforehand - see if anyone has tried, what their results were, etc. Most times if you push a monitor past what it can handle, the screen will go blank and take you back to the "revert settings" screen. As HOI mentioned, going from 60 to even 72 is a nice difference...as was going from 75 to 100, but keep in mind you are still doing this at your own risk.