If the rumours from Lyneham are true, then its not even a strat ac and another leap backwards for the RAF!
Sure, it has teething problems but it can't go as far, carry as much, as far as the K - primarily as the J is heavier, has a lower MTOW, no external tanks and a shorter crew duty day (oh but think of the money it saves by having no engineer and nav)!
Furthermore, its arrival in AFG/PAK theatre was widely heralded only for it to break down on national TV! However, I gather this very common because of sand clogging its new engines. They fly about one sortie a night (compared to 4-5 done by the K Model) and have to be baled out by the K based elsewhere in theatre helping out with the tasking. I'm sure the crews are working hard flying their thoroughbred pilots'-play-thing but a friend of mine based in theatre says the K was a much better workhorse - crews were better drinkers too!
As for the Tac side - foget it! 2 pilots (one permently heads down) at low level just doesn't work and is just dangerous no matter how good the software is. The workload trials have been delayed, AAR is a way off and dropping trials are on hold! Even tho' it is only a pipe-dream at the moment, the A400M is earmarked as the next Tac/SF ac so the J will stay strat, as will the C17 - mainly cos 2 gp Staff Officers don't understand tac. Now as far as AAR is concerned - that is the way ahead - where the J might actually have a role a la the USMC helo-refuellers.
As for the slur that the crews don't have any balls - that is @rse! RAF C130s have been operating into AFG/PAK in unprotected ac since before Christmas, this despite pleas to buy it. USAF and SF (and now the J) ac are as fully protected as you can get. Furthermore, if the USAF DAS breaks, they don't go. Whereas the RAF K herc crews have soldiered on incredibly bravely whilst being shot at and having several near misses with SAM and AAA. Also, Airliners look like airliners and as such are not as good a target as mil ac. Whereas RAF Hercs look just like USAF gunships! Guess which one Osamas cronies target!? If you fancy flying an unprotected ac into a high threat environment, ask the Tristar boys who've done the same - but only once until they realised the dangers - also brave chaps. So sod orf DD!