Sometimes you might not notice it as much depending on the sauce and toppings that you are pairing the IPA dough with. I use the term pairing, because beer like wine, needs to be paired with the right toppings. If you were to compare the taste of pizza dough with beer next to dough that has not been made with beer, you will definitely notice a big difference in the flavor and texture of the pizza crust. Also, when I take the dough out of the fridge for the first time, I can smell the wonderful aroma of the pizza dough, which will bake into a great crust. It is worth adding the beer.
As for IPA beers, sometimes I like to use a Double IPA or the term Imperial IPA (which is a DOUBLE IPA). These can really provide some wonderful flavor in the dough. Over all, your average single IPA is going to do a great job for your pizza dough. However, there are time that I like to spend a bit more and get the best IPA that a beer company makes. The Dogfish 120 Minute IPA is very limited and costs around $10 or more for only 12 ounces. I do not always use it in pizza dough when it is released since most beer stores will only sell you one bottle, but I am one who likes to experiment a lot with different beers in dough.
If you compare the 90 minute IPA to the 120 minute IPA, you can see the difference in color and definitely in taste.