I think Jones is out to prove himself. The difference between Jones & Luiz is (so far) Jones' enthusiasm has been slightly more measured, and Luiz' rogue approach has more often than not been a major factor in Chelsea conceding a goal or losing a game. Unless I'm very much mistaken, I can't fault Jones too much for an important goal we have conceded, maybe the odd couple where he could have done better, but no calamitous errors.
Also, Jones has done unbelievable things that JT & Rio would be proud of. Luiz has done some good things, but mainly at the attacking end of the pitch. Jones has done amazing things all over the pitch. As far as I'm concerned, big Phillip is ready for an entire career at CB, and a bloody good one at that. Luiz isn't even in his league imo.
I rate Jones as potentially as important as Rooney in terms of transfers in the past 10 years, I just think he can be a rock for us for the next 10-15 years. I would even go as far as to say that had Arsenal or City signed him he may have won them a league or two. Not only did we gain a terrific player, but we also stopped our biggest rivals getting a huge asset. I believe he can be as big as Tony Adams & John Terry for us.