We bought this for a basement work area, and decided to customize it to fit into a specific space. The end product was 3x6 feet. We did opt to use the center diagonal support, as suggested. With power drill and power screwdriver and two people working on it, it was not all that long or hard to assemble. Possibly the most time-consuming aspect was getting all the lumber from the big box store, loading it into our van, and then getting into the house. We smartly had the big box store cut the 1/2" AC plywood into 3x6 feet, and also had them cut the 2x4x10's into 2x4x6's and 2x4x4's - suggest you consider this - well worth the price of cutting. We recommend this product - it makes for a nice workbench and has the flexibility to meet your needs for what size you want it to be. 

Pros: Easy to assemble, sturdy, inexpensive, flexible
Cons: None.