I couldn't disagree more. The only reason that you should stick to just one company is if you have to. ie: sponsorship
When I started i was usng ebonite from the word go, then i tried a columbia throttle and loved it (the only ball i like from columbia) and at the moment i am loving storm stuff.
The best way to compare balls is to watch other people with similar styles thow the ball, and see if you like the reaction/roll, or find someone with a similar span that is throwing the ball you are interested in, and throw their ball down (with their permission of course)