Stiff, well, as they're steel, it's bound to be less stiff than a similar alu frame. Strong, Mr. Marino seems to be getting welding down, so it should be pretty good. Being steel it's also very easy to get repaired if it breaks. Weight, depends on what you order really, but as it's steel, it's likely to be heavier than a similar alu frame. Postage, a week or two, I think.