Seems like I've always ridden triples. My rule of thumb is: small ring going up hill, middle ring on the flattish, big ring going down hill. One of my bikes has 9 cogs and can use all 9 in the middle ring (it's deliberately geared that way), the others are all 8 or less and have no issues, either. Old technology/old habits. YMMV.

I spend most of my time in the middle ring.