The function of the voucher hasn't changed, so you can use it as a 241 on a return ticket or to upgrade 2 people, one-way. (This is for reward seats, there don't seem to be any data points for cash bookings yet). The 75k value refers to how much of each type of booking it would cover - so if you wanted to upgrade from PE to UC, and the difference between cabins was 30k points each, it would cover that. However, If the difference was 40k each, you would need to add 5k points from your account to cover the shortfall.

You don't get any "change" from the voucher if the number of points you need is less than 75k, which makes it rather one-sided! There have been a couple of instances where Virgin agents just don't seem to know what to do, e.g. when the PR price is actually higher than UC, so at the moment you just have to call and hope your requirements fit in with the possibilities so far.