The only way to be sure is check the installation instructions for the type of flooring you are planning to install. It will tell you what you can and cannot use for underlayment. If you vary from the mfg's recomended underlayment you can void any warranty.

If you are talking about Konecto or Allure, the manufacturer specifically says no underlayment. Evidently the "give" can cause the seams to separate. I put Allure down in my laundry room last summer...it has held up well in that small area, with no telegraphing:

I decided I wanted something more permanent for the rest of the basement. I just had duraplank glued to my icky old asbestos...don't have a finished picture, but here it is "in progress":

I will say, the cost differential was substantial. My Duraplank ran $7/sq foot installed. The Allure (DIY) was less than $2...

I am very pleased with the performance of the Duraplank...but it's only been down a week. It HAS already survived a minor flood--Faye filled up a window-well (the one on the right in the picture) and sent water onto my new (down less than a day!) floor. I've fixed the downspout that caused the problem...but it was an anxious few hours while I waited for the floor to dry. It dried out just fine...but that possibility was one reason I went with Duraplank and not engineered wood. (Which would have cost about the same.) I'm pretty certain wood would have been ruined...as would any sort of laminate.

Good luck with your decision!

melanie