I really think saying that you cannot compare walkers is wrong. You cannot compare all walkers, but Tezz vs other Tezz is at least in the same ball park, and tezz vs Jace is still a lot closer than Tezz vs Lightning bolt or something. It's like saying you cannot compare mox ruby to mox pearl because red uses artifacts better and needs more mana. All cards are contextual and all decks are built on synergies, but even saying that on the surface these 2 cards have a lot in common.
Both are mono blue
Both cost the same amount
Both are above bolt range for loyalty
Both want to be in a deck with artifacts, specifically ramp artifacts since they help play this card earlier.
Both can provide some form of card advantage
It is rare with a walker that you build a deck around it or that it's just strong enough to be plopped into a deck because of power alone. There needs to be some level of synergy and power on both ends for it to merit inclusion into your 75. I think we will likely find that both these tezzes end up in decks that have a lot more in common than not. Ill go out on a limb here and say that every deck running either of these cards is going to have
4x Force of will
Xx Mental Misstep
5+ x Moxen
Yadda yadda yadda
The difference I really see in this is original tezz does lend itself more to combo kill with a backup of control features, where as this tezz lends itself to control with a possible combo at the end.
I do not think they are light years apart, and the heuristics make sense in the context of this card getting played.