Hmmm... I have both, a stock height KJ Sport with full skids and Toyo Open Country A/T tires and a stock height JK X with skids and 32" BFG M/T tires.
My impression of the two differs a little from yours. I don't want to turn this into a KJ v.s. JK is better war, that's far from my intent. All I'll say is, while both are capable off road vehicles straight out of the box, the JK can go where a KJ can't with the drivers of both Jeeps having the same off road driving skills.
I find the ride more comfortable in the JK with it's bigger and softer seats, especially on the 400~500 mile road trips to get to Moab and Ouray. Also, I have much more room in the JK, especially with the rear seat removed.
As for the challenge... just do harder trails in the JK, it takes the same amount of "finesse" to get the JK up and over as it does with the KJ. The only thing that changes is the difficulty of the trail and the skill of the driver.
Don't get me wrong, I wouldn't give up either one of my Jeeps, they're both great off road vehicles and I enjoy them both. So much in fact, I sold my two seat '04 Crossfire and '99 TJ to buy the JK.
And yeah, LOST KJ has evolved into LOST Jeeps. One thing to keep in mind is that we all drive Jeeps, whatever the model. It's the skill of the driver and the level of modifications that really makes the difference on where you can go.
Happy trails and enjoy playing in the dirt with whatever model Jeep you drive....
