Workbenches have flat tops, though sometimes at the rear there is a cavity called a tool well that contains tools and components (and prevents them from falling off). One advantage of having the well set into the top of the bench is that, even with a variety of objects in the well, a large sheet of material can still be laid flat over the entire surface of the bench; the contents of the tool well offer no interference.
My first attempt at making a cutting guide didn't work. What I ended up with worked fine for cutting panels, but the guide-strip was too narrow, and when the saw was extended fully for rough-cutting the 4x4's the clamp heads got in the way. So I made another. Actually, I made two more, so that I could cut one into shorter pieces that would be easier to handle.
This table top is also made from the hardest wood out of any manufacturer we reviewed: oak. In fairness, this can be both a blessing and a curse. The oak wood is extremely durable and noted for its lack of a porous nature. This means the top can withstand plenty of abuse from tool and workpieces. Moreover, you will not have to worry about liquids like lacquers and stains from being absorbed into the top. That said, the hard oak can also do a number on tool sharpness, dulling them prematurely if they are not carefully handled.