They're different fighters TS. Both are great, but Jones is more well rounded and more proven. Conor is much more dangerous though and his striking is much better technically. Jones has never had great footwork or boxing, just to name two things that come to mind. McGregor's timing and precision also exceed Jones'. For everything relating to grappling though, Jones beats him handily.
Jones has been around longer and defended his title many times. Some of his defenses were tougher than others and many of them were very easy for him. We'll see what McGregor can do in terms of title defenses. He has more than his work cut out for him since he's fighting in two divisions now and not just one. Even if he lost to RDA then Edgar (a former LW champ that just knocked out Mendes) is next up at Featherweight for Conor to defend his title against. His competition is only getting much stronger now that he's a champion.