Actually I was kind of going for duplicate gearing, in the sense that the same ratio on two different rings would feel the same. One step on the rear cassette is ideal for me, just wanted to preserve the low range with a tight 8 speed cassette while having the two larger rings serve reasonably different purposes (without the crossover point in an awkward spot). I like the 48-28 idea even better though, as it's even more of what I was after in the first place.