This year at the tour Or 2011 vuelta on the Angliru?

The 42 inner is the same over the whole rotation as a 42 round, and "feels" very comparable. probably nearer 46 at the max and 38-39 at the deadspot. Moving to a slightly bigger cassette will minimise any difference you feel up hill.

However the ovalness does help keep fluidity and momentum climbing better than a round ring IMHO.

If i install a q ring, it will one be the inner 39t. just want to test the waters

So a 42T O.symmetric inner will feel comparable to a standard 42T inner? With Campags biggest 29T rear choice that will effectively give gearing equal to 39/27, which I for one find a tad on the heavy side for long sustained climbs of around 10%. Not that I climb those all the time, but being able to choose suitable gearing for those events is something I'd like to do. Hmm.

Ill be using the 39t q ring with a 25t rear. Hopefully i feel a difference.

Yeh the osymetric 42 gives the same roll out as a round one. They do a 38-52 in 110bcd if thats any help.