1X3 frame welding table

[Nicad]

I want to build a welding table and was wondering if it would be preferable to just make a Grid of 1X3 or 1X2 steel rather than have a plate on top of the frame? I have a large piece of 1/4" plate, but it certainly is not flat., but it is heavy. Seems to me if it was built on a proper flat table the frame would be pretty flat, lighter and a lot easier to clamp things to. IS there a downside? Would it twist? I suppose you could not hammer on it, and small items would fall through the grid (Which I think would be spaced about 8X8 apart). You could just keep one small plate for those jobs.

Opinions appreciated.