Khamzat has the better shot and more powerful wrestling, but Khabib is the better overall grappler because he has the higher IQ. That's usually how I distinct between two very good grapplers, the guy you think is smarter will usually slightly edge out the other guy.
Khamzat relies on the bullrush shot from across the ring to get to the ankles, while Khabib was fine taking you down with singles, doubles, trips, judo throws, etc. Khamzat is incredibly impressive and i think his gameplan will keep working up until someone like DDP feels that throwing a flying knee against the guy is going to work, and it connects. Everyone that has faced him has been on the defensive the first round trying to survive, the key to beating khamzat is to meet fire with fire I think. Don't allow him to be the hammer, but we will see.
Khabib showed no weaknesses in his grappling game outside of not being able to take Gleison down (Khabib went 0 for 13 in takedown attempts), but that also showed us that another incredibly strong grappler can definitely give Khabib trouble, Gleison just wasn't well rounded enough to put it all together. For now, we know that Khamzat does not have a great gas tank, and will probably slow down in later rounds.