I'd label Jones as the more talented of the two from an athletic standpoint. Also believe that speaking on P4P terms, he had better power, slightly better movement, and better overall reflexes, thus enabling him to take a lesser amount of punches in his prime. Roy barely lost rounds as well before his downfall. Ali had the better jab and a significant advantage in durability with all things considered, despite Roy never really being hurt or in trouble during his best years. With that said, Ali has a big advantage in the resume department. That cannot be overlooked. If you base P4P lists off of H2H ability, I'd give it to Jones. If it's based on resume, I'd give it to Ali. And if it's a 50/50 mix of the two, I'd go for Ali.
Ali without a doubt. Jones relied on his natural gifts more and Ali had just as many + 1, a legendary chin. Ali also had a greater creative capacity enabling him to overcome big odss to victory vs. Liston and Foreman etc. He also had what amounted to two careers with his 3 year exile in between. After the exile, he was a changed fighter due to a decline in his physical gifts, yet he still managed to accomplish so much that it shows haow great a fighter he really was.
"pound for pound" Ali without any hesitation. Jones doesn't have comparable wins on his record like Liston, Frazier, Foreman or Norton. Ali proved himself after setbacks against Frazier and Norton then later Spinks at the age of 36. Jones' resume is good, thats about it. Not great. Not too difficult to seperate them both.
Even though RJJ always have impressed me hugely when I've seen him I don't know him as well as Ali. Was he really faster p4p than the 212 lbs Ali who fought for example C. Williams? Also Roy never did prove the same set of intangibles did he, nor the same chin? Those are often the deciding factors in close battles, and if you could somehow make them fight at the same weight with both in their primes it would be close, make no mistake about that. I have a hard time seeing that the intangibles wouldn't give the edge to someone so hugely naturally gifted as Ali, but maybe those who know RJJ better do.
Pre-exile Ali had a so-so chin and not very good durability in general. Post-exile Ali looked like **** on legs and in speed department, most of the time. As always, people confuse two versions and blend together only the good qualities and throw out the poor ones.