All in all the benefits to having a secondary that compliments your main can be quite useful! There are a few top players who have mains to compliment their secondaries as well...Momochi, Kindevu, Justin Wong all come to mind. Reading the Singaporean SF4 blog, I was reading how Japanese players say that they like to stick to their characters through thick and thin, no matter how high they are on the tier list, they tough it out and try to main their character to the fullest. I think it's a good mentality, and it's not to say that having a secondary would be bad...but I will say that being able to understand the situation you put yourself in is important as well. Valle had a quote that I remember him saying: "If you can't beat a character that you have a disadvantage against, you're going to need to pick up a character that puts the odds at even or in your advantage." The mindset is pretty simple to understand...even if your main can't stand up to your opponent, your going to have to put the odds in your favor in some sort of way...having a secondary character is probably the best way to do so.
- Mickey