I made my version of a Roubo bench over 20 years ago. According to the latest bench rules it is too tall, too wide, has too many vises (I use both sides of my bench and that might be a no no, not sure ), and has far too many holes. Did I mention that I have a double row of dog holes with a user made dual row wagon vise? I had no idea they were called a wagon vise back then. Being a tool maker and tinkerer at heart I just made a vise that I thought at the time was an original idea for the main side. Couple of dowels in a piece of wood straddling the two rows and I have a bench stop, or a different variation gives me a 3 point clamping system. If that isn’t bad enough it also has drawers on the bottom to store seldom used tools and supplies. Maybe if it had taken me a few weeks to drill all those holes and mount a few vises I would only have one vise and 8 holes too. I dunno
Regardless of which type of screw you use, you'll need to flip the panel and use a countersink drill to on all of the exit holes. Drilling MDF leaves bumps, the countersink bit will remove them, and will create a little bit of space for material drawn up by the screw from the second sheet of MDF. You want to remove anything that might keep the two panels from mating up flat. I set a block plane to a very shallow bite and ran it over what was left of the bumps and over the edges. The edges of MDF can be bulged by by sawing or just by handling, and you want to knock that down.
The 84-906 fits this bill perfectly as the table offers all of the qualities and features that you would expect but does not truly blow you away with any of them. For instance, this bench is made out of rubberwood. This wood is decent in that it provides the strength you want, but it is also extremely porous and rough-grained. The porous nature would generally make it susceptible to rotting and staining, though the bench has been lacquered. The rough grain will potentially cause tools to dull over time if you do not regularly relacquer it.
While a strict figure for the bench’s weight capacity is not available, a quick browse through their other stand and bench products shows a general weight capacity well above most other brands. As such, while we cannot say for certain that this bench provides the best weight capacity, it is more than likely that it the capacity is similar to the other products in the catalog.