The K is now 40 years old, has done an awful lot of work, from Ethiopia to gulf warII, and came through them all with honours. It is an extremely old aircraft that has had to work hard, of course its now going to struggle with fatique. However it still keeps going, and thats despite the best efforts of marshalls to keep it on the ground.
The J can be a very capable aircraft, if allowed to be. It is only about 7 years old, however the unservicability has not been too good, (especially when you compare it to the c17, an aircraft of similar age), but we can put that down to teething problems. Maybe one day the J will do all that is promised of it, and if it can stay servicable then it should do the job more than adequately. Its big advantage over the K is its uprated engines, but surely that is to be expected over the ageing allison engines.
My point is that i believe it is wrong to give the K such bad press when really if J model operators (the majority who were ex K model aircrew) were completely honest with themselves, they know there aircraft isnt living up to expectations and has been a poor replacement so far. But that is not to say it wont be as usefull as the K has been, but it really needs to earn its spurs before it can be put up and compared with what the K has achieved in its lifetime.
D-F