Dang, I got it right the first time
So I had to do a little spreadsheet just to see. Told you I'm a data geek.
With my standard Shimano 30/39/50 triple and a 12-25 cassette, I have three gears on the puppy gear that are lower than anything I get on the middle ring, and four gears on the big ring that are higher than the highest gear on the middle ring, for a usable 17 speeds. Exactly what I posted earlier that I've been using...
With a standard Shimano 50/34 compact and the same cassette, one would have five speeds on the small ring that are lower than the lowest gear on the big ring, for a usable 15 speeds.
With a standard Campy 53/39 compact and the same cassette, one would have five speeds on the big ring that are taller than the highest gear on the small ring, for a usable 15 speeds if you go at it from the other direction.
Low gear on a 30x25 with a tire rollout of 2091 mm and an effective diameter of 26.2" is 31.44 GI. Low on a 34x25 would be 35.63, low on a 39x25 is 40.87.
High gear on a 50x12 with the same rollout is 108.99 GI, high gear on a 53x12 is 115.80.
TMI yet? :p;) Bottom line is, with 21% grades like our club climbed last night (the ride leader's Garmin said it was 24%) I NEED those low gears to get up the hills and the high ones to get down them; and the more close-ratio gears I have in between, the more comfortable my knees and muscles are on the flats. So I'm even more confident than before that I made the right decision in going with the triple.