I like Russ and his interpretation, but he doesn't come close to the level Nimoy took Spock.
Spock, by overt and regular mentions, is only half Vulcan. He can basically play whatever he likes in there...nothing is out of character, because he defines the rules of that character. Any actor playing a full Vulcan has to play within those rules.
I also don’t think Spock was actually taken to any levels by Nimoy, except on rare occasion. The ‘suppressed emotions’ bit is better done by Lenard and Russ. Spock repressed his emotions like arcing soup through the air...the rest of the time there’s a very arch performance, a heap of camp, as befit TOS in the sixties. He does some stuff in TMP, but everything after his death in Khan is very paint by numbers. An arched eyebrow here, a soundbite there, all reaching its low/high in VI with some very silly dialogue in deadpan. A lot of Spock moments deal with him being a raving loony because his emotions are not in check.. which we also get sometimes with the other lead Vulcans...but they do it so much more amazingly subtly, with greater contrast.
Lenard having a breakdown in ten forward is better than soup through the air, possibly even better than straightening a uniform to die in a glass box. Russ has many such stand out moments...he bit where he wants to tear Taurik a new one for assaulting B’Ellana, and manages to make a scene that could be really really uncomfortable as written, into something much more through how he controls his voice for instance. There’s a reason that little foot shuffle when Neelix leaves actually carries so much emotion, and it’s because of all of the performance and writing to that point. Literally a foot shuffle conveys as much as Spocks entire TWOK death scene, because of the character and the actor. Nimoy, like much of the TOS cast, rarely goes in for subtle. When they do, it’s amazing...Shatner is an excellent actor, and the Meld scene in the beginning of TSFS is amazing because of him going subtle. Nimoy too, in the first two films at least, does a better job of this. DeForest is good with gestures and facial expressions, and it’s one of the things that carries off some of the amazing character stuff in V. Nimoy...doesn’t turn in a good performance there. Russ ftw.