I try to apply my game to a ball reaction or "desired" reaction from the manufacturer. Almost any ball will work if you have the right people fit and drill it for your game. How it fits with the other equipment in your arsenal and the manufacturers other balls are things I tend to focus on. How does this ball compare the pearl version or a ball a few years older even.
I also try to use it on tougher conditions which will display the differences between balls in my arsenal to a greater extent. I have run into very few duds as far as bowling balls go. They almost always work for something you encounter. It's just a matter of finding out if this is the right ball for you to fit into your current arsenal. Do you need more length and backend, or do you need something with heavier roll.
Also, it's important that a ball reviewer also identify his layouts so that the information he presents can be replicated by a reader who wants to generate the same type of reaction. However, taking into consideration that lane conditions and house characteristics come into play too.
I think they are useful. Specifically if well written. And I would think, the less informed bowler would use the review more-so than the guy who already knows everything.
PROFILE
340-370 revs
18 mph
230 book on THS
200 book on PBA
Arsenal: (In the bag) C-System Ulti-Max, C-System Alpha Max, C-System 3.5, Lethal Revolver, Loaded Revolver, Wicked Siege, Massive Damage, Damage, Slingshot, Avalanche Slide,