I think that the server load argument was discussed plenty.
Not in the threads I visited.
However, when you change a game mechanic to reduce server load, the mechanic change itself deserves as much discussion as the load reduction. It's not "reduced pump server load by 50%", it's "invented a new mechanic obsoleting lava pumps, which is coincidentally 50% easier on the server".
Which Magma Crucibles never did. Pumping lava was still there, for free. The minimum cost was 4kMJ. That means that the Netherrack was less efficient than pumping lava. So it was slightly worse than lava pumps but made up for it by being better on server load. And server load is something that everyone, not just SMP admins, should be cognizant of when they are on a server. The SMP server I am on is now debating a map wipe in under a month because of people building structures that are fine in SSP but in SMP have caused the server to crawl to the point where block breaks on the server lag 1-2 seconds after the client, if at all.
The way the game is designed pretty much necessitates two things, even in SSP.
1: Forced chunk loading (even in Vanilla).
2: Teleportation blocks for items.
Tesseracts didn't obsolete anything. They do, however, fill a much needed role. One which has been available to us for many, many versions and hasn't yet been included because no "official" version exists for 1.4.x.
Since this is the FTB forum, I think we should be talking mostly in terms of FTB modpacks. And one of them contains both TE and EE, thus is is a valid point.
And other packs don't. Which is kind of my point. Balancing for one or the other screws the one you didn't balance for. We can have those discussions all day by tossing any ol' pack in the mix. We don't. Besides, if there is any fundamental balancing flaw I would say it is best to err on the side of the mod which makes it trivial to enact the other mod's recipe. IE, EE, not TE.