It's easier than ever to redeem Long Haul J on Avios now. Four J seats on every flight, rather than the previous two. Additional J when using the Premium Voucher... just need to pounce at the 355 stage to have the best chance. Plenty of choice if booking further out. Not on keen holiday dates and mega busy / expensive destinations, but I've never struggled to spend mine and achieve great value. Not sure what you mean by "double upgrade" but that's never been possible ?