I am in Ben's category. I think in patterns as well, but also in numbers. I know I can do different things to a I, Iv, or V chord than I can to the others at times.
For example: The flatted third of the I chord (Bb in Key of G) can be used extensively in the V chord (D), and about half the time in the Iv chord (C), to find melody. However flatting the third of the V chord you get an F sharp which doesn't work worth a diddly over a 1 (G) or IV (C) chord for a main go-to melody note in most melodies in Bluegrass or Country styles.
Hope some of this makes sense.