Delamination or bubbles and separation come from various factors, most are bad. They tend to get worse and have a HUGE negative impact on your ability to resell without full disclosure and/or repair. Also, often combined with leaks of some sort.
Just know what you are buying and your future expectation to come out of this sometime in the future rather than sell it as junk. I am not implying this WILL happen to you, just know what you are getting yourself into.
My advice is to shop around and continue to find that flawless unit, one someone is selling because of family health issues or they are aging and getting out of camping. These units are around and can be found.