Michael,
The 433 and 490 are two different tubes.
Good that you came up with the new Easton spec sheet. For a long time the old one was taken off their site.
The new spec sheet appears to be their new line of alloy tent tubes. The 433 has been eliminated.
But as Jerry points out, Quest still sells the old line, and probably will continue to do so until their inventory is sold out. Maybe Tent Pole Tech has the new line.
At the risk of sounding like a broken record, you may be overlooking that these Easton poles are designed to bow in hooped tunnel tents and domed structures, or "pop-up" tents, as Roger Caffin likes to call them (derisively?). It is a mistake to think that just because the poles are larger diameter that they will be stiffer, if they are designed and intended to bow. The carbon ones intended for mids, should be much stiffer, like a trekking pole. If you want or are comfortable with your mid pole bowing, then the Easton poles will save you money. If not, a better carbon pole will not bow anywhere near so much. If it does, it is a rip-off, and not worth the extra money. A big plus with carbon can be the stiffness attainable at lighter weight.
Was thinking of this thread today looking at an aluminum alloy avalanche probe, about 1/2" diameter in a shop. It bowed a lot, not as much as a fly rod, but sort of, and I would not want 45-55" of it holding up my mid (if I used mids). It's fine to have poles bow if that is part of the design, but if the design calls for a straight pole, as does a mid, the bowing can cause problems. While it might help when bowed to keep the sag out of a silnylon mid, there are other ways to do that, and a number of mid users have posted here that the bowing and flexing in high winds is a problem. Please let us know what you decide and how it works out.
Can you imagine how much money Easton and the DOD spent deciding what new diameters they wanted for their tent poles?