I think Safin was a huge Talent and a Nutcase. And I like him because of that.
But Peak Safin vs Peak Djokovic is like Peak Patterson vs Peak Ali.
Safin can throw at him, whatever hes got in his Arsenal .. but there is nothing he can hurt Djokovic with in the course of a whole Match.
Safin stands there as one of the glorious Members of the weakest Eras ever, where Federer was able to amass Slams vs a flock of One-Eyed Chicken.
Safins BH may have been more effective, sharper and flat with more acceleration - thus maybe better. I don't think it was more consistent tough. And peak vs peak his Backhand just doesnt hurt Djokovic. Because Djokovic is a Master of Directing/Redirecting Balls at will.
And because I believe Djokovic is the greatest natural Athlete to ever grace a Tennis Court. Followed closely by Pete Sampras.
So, peak Safins BH may have been better - but it's not important - because peak Djokovic is by far the better Tennis Player.