I use a lot of I-form in my base packages and, yes, I have had success with it at times.
I don't think it's a formation issue, so much as a personnel thing. You can't defend the I using nickel or dime as a base. Using 4-3, 3-4, or 4-4, elite RB and TE groups are often going to have an advantage against the defensive LB groups. The same phenomenon comes into play with the pro set.