Great thread!
I'm currently running 46/16 on 700x35c tires (78.1 GI according to bareknucklebrigade.com's Rabbit). Great on flats once I get going. Not so great acceleration compared to other riders I see. And a little tougher than I want on hills.
Question... I'm going up to 17T (73.5 GI) because of the hills and lack of acceleration. I have a flip flop hub though, so I'm wondering what I should put on the other side. Would going up to just 18T (69.4 GI) on the other side make sense? Should I go up 2 teeth with my "other" gear? 46/19 would put me at 65.8 GI. I'm not old nor do I have bad knees (Puppypilgrim's ranges).
Also, how much would I be moving my axle in the track-end flip flopping to 1-2 more teeth? Switching to bigger tires had me add a half link and move the axle about 2/3 of the way back in the track-end, so I don't have much room to play with.
This will be freewheel/freewheel by the way.