Next closest to the front is Jazz.
And really, if a guest had the furthest end in Calypso, it would only be a few steps difference than the closest end of Jazz.
My guess is everyone now requests Jazz since they have to pay more for Calypso.

For our October stay, we paid the extra $10 a night for Calypso. And we had a good location.
Some friends we were vacationing with were in the Broadway building. We walked back there quite a bit, as they had a car.
It really wasn't that far of a walk. It looks worse on a resort map than it really is.
We are chancing our location in Janaury and I really am not worried about it.
The Calypso building is very convenient. But unless you really want that building or have health issues, I probably wouldn't worry about it.
The further back you go into the ASMu, the quieter it is. And there is a nice quiet pool towards the back, near Broadway.