I don't always trust an IPA. You don't always know where it's been, and if cold then warmed and them cold again, it will lose intended flavor, replacing it with some oxidation. At least that is my theory.
I had a few IPAs that accompanied me to a tasting recently and then came back home with me (I know, the horror). None of them were as good as they were the first time. One was almost not drinkable (the Ass Kisser Double IPA). I can't recall if it was great the first time, but I'm confident it wasn't the drink that tasted like it came from ass that it was the second time. Others from the same tasting didn't taste as good after re-refrigeration. It was actually quite disappointing.
I picked up some beers from a local brewery and was excited about their Imperial IPA. Ugh! It was horrible!!! I dumped it. I can not believe it was intended to taste that way. Not possible! And again, this went from the refrigerator at the brewery to my trunk for a few hours, and then back to refrigeration. It was a few weeks before I had a change to actually try it. So, time and changes in temperature seem to be a recurring theme.
It's gotta be those fickle hops!
Lesson 1: Drink IPAs fresh. And be cautious to keep the environment friendly.
Now it's been told that some stronger IPAs will age well. The Dogfish Head encourages the aging of 120 Minute IPA, and I can't say that I've actually tried it fresh. It's one of the special occasion beers for me. I've promised myself I will purchase one each time I see it. They brew 120 Minute maybe 3 times a year at the most and with limited distribution. Even at $12 a bottle (12oz) they go fast.
There is a Hopslam still sitting in the back of the refrigerator too, waiting for another special occasion.
Over time the hop bitterness in beer will subside and oxygen will become more evident. The good kind of oxidation results in a sherry-like flavor. The bad kind results in wet newspaper staleness.
When properly cared for an IPA can be wonderful. Be cautious and know where your IPAs have been.