Whilst all mine (MTB, hybrid and road) are all triples, the next road will be a compact double (2 x 10). I don't use the granny ring on the road triple anymore, and probably could have managed without it from day 1.
I'm pretty sure if you have a compact and a 30-12 (or similar) cassette you will still have a decent low gear for the proper hills...
I think there's a lot to be said for the out-of-fashion triple. You have to do less of that double change thing (down at the front and up at the back), you tend to get a wider range of gears and the ratios at the rear are closer if you're one of those steady cadence cyclists. And the extra weight of the third ring is, what, 300gr tops?
I guess I was simplifying a little. The middle ring on a triple will be slightly heavier than the little ring on a compact before you add the weight of the little ring, but all in all, I doubt that the overall weight gain ever exceeds 300gr. And I reckon I regularly lose more dead weight than that in the morning toilet visit....For Ultegra the small ring is only about 100 grams .