JUST looked at those countertops.... given that it says you can cut them to any length you want, and cover the cut end with some edging they provide, it SOUNDS as though they're fairly solid, rather than some of their other products that are somewhat hollow, so they might be fairly anti-sag as-is, depending on what that "solid" material actually is. Unfortunately, knowing how a lot of Ikea stuff is put together, I wouldn't count on it.....
Honestly not really worried about the 74" one too much, but that 98" one is long and will have my monitor and a second monitor and possible my rig on it too. Plus printer and who knows what else. And really this came up from some people complaining that they have gotten sag with Karlby and other Ikea countertops. So this is more of a forward thinking do it while I am in the middle of building instead of after once I notice a sag. The countertops themselves are a 1.5" thick particle board and are solid throughout.
That said, if I don't find what I want/need in time for me to be building the desk (new floors and painting has to be finished first) then I will just build without it and add after.


