The FICO website suggests that credit mix determines 10% of your score. And while they don't offer much more detail, Credit Karma shows this on my account:
Credit scores are important if (and mostly if) you plan to borrow money.
This image is from FICO, and shows the possible cost of a low score. On a $200K loan, 30 year term, the difference is about $24/month or $8344 over the life of the loan. The one point Pete has made over the years is that if you are at 770, you are already in the top range. Why give any further thought to this game? He is 100% right. But, if one is in that 620-639 range, getting the score two levels higher is a $110/mo savings, which can multiply up to a nice addition to one's retirement.
To answer you, OP (original poster), unless you are looking to buy your next home and need a large mortgage, you are all set. To any future reader here, the value of tracking one's score only pays off when looking to make a purchase on credit such as a house or car. (A really bad score can impact future employment, but that's a different discussion).
On a personal note, when I went to renew my HELOC, the application was all over the phone, with docs sent via email. When the rep asked for permission to pull our scores, I agreed, and soon heard her say "Oh, wow. I've never seen that before." My wife and I both had 850. Still, 775 would have gotten us the loan, just as fast. If I weren't a member here or didn't have a blog (on hold for now) focusing on personal finance, I'd not have bothered with the years long experimenting and tinkering to game the scores.