Originally Posted by
lsquare
Even without a GUF, I can still upgrade from W to J if there is award space right? It's just that a GUF and Joker allow me to use Avios to upgrade into revenue space?
Exactly. And that is far more plentiful on BA vs. US carriers. But remember you will also get wacked with the carrier surcharge which is even higher on US-originating tickets.
Point is - if you want to be in a J all the time without paying for it but are willing to be a decent amount for W + YQ - BA has its advantages. If you want cheap upgrades but are willing to fly Y and W some of the time when you don't clear, UA is better.