When cube came out, it ran good on 2001´s mid and high end systems.
The fact you bring up the "get a new computer" argument shows me that you haven´t understood cube´s philosophy. (plus, it´s a pretty arrogant statement. Not everyone can afford a shiny new box, you know..)A lot of ppl like cube for not pushing them to get a new box, only for some totally unimportant features like ragdoll physics and dot3 bump maps and the like.. but for giving them a simple game reduced to the needed basics of an fps..
Cube is simplicity, and simplicity also means it´s simple enough to run on a pretty old system.
I am not against open landscape maps at all, but I am against open landscape maps in cube, because cube just wasn´t desinged for it. Full stop. If you love open landscapes, map em in an engine suitable for it, like serious sam, or tribes or whatever engine that was laid out to optimize the performance on those kind of maps.
If you map for cube, you need to stick to what it was designed for, no more, no less. If you think it sucks, use a more modern engine.
The wqd figures I have proposed to be ideal here often are already adapted to what is considered low to mid- end machines nowadays, but they make sure you won´t need that 2000$ high end pc to have fun with cube.. whereas "fun" doesn´t mean crappy 30fps or so, but at least stable 75 and preferably lots more (talking about serious gaming..)
Edit: Was meant to be a reply to cc´s comment, but after I edited it once, it got a "new comment"...