I get people like Federer. I get people like Nadal. Novak's machinator style of play makes him harder to LIKE. But this is something they've never done. The way he neutralizes every big weapon opponent on every surface puts him as the best ever. Borg and Federer had stretches, and were a lot more elegant in winning their points, but never played at this high a level over a long period of time. Has double the ATP points of Fed and Murray - neither have the tools to beat him. Wawrinka, Cilic and Kyrgios can trouble him on their best days. Otherwise he has the next 5 years.
Field is weak right now. I see him winning 2 slams the next 2 years then his game will start to decline. He has a shot to pass Fed on total slams. We will see.
Compared to the 90's, yes. Don't forget, Fed had a cakewalk during the 00-10. 3 finals against Roddick, 1 against Bagdotish, and plenty against Nadal not on clay. Novak ups the ante every time his opponent gets in a groove - a stronger field wouldn't hurt his title chances. The only threat is a guy like Wawrinka playing lights out + hitting a lot of risky winners. Whether or not he passes Fed on slams, he's already ahead of him on all time status. Unfortunately, his ruthless game works against him in terms of media recognition.
I never liked Novak's game because he was so immature watching him 8 years ago, especially when he would throw a fit during a match and retire. But something clicked with him in the past 5 years and he's just been on. He has a complete game and matches well against any top opponent. Novak's dominance is peaking at a time with no major rival. If he peaked at the same time as Federer, I think I'd give Federer the nod but they'd still split slams during that time and neither would run away with record high slams. He's been on an amazing run. I haven't watched much tennis in the past few years. Not sure if it's due to less time or not as exciting competition, probably both.