By the looks of it your miter saw will be stationary and you have a table setup for it. Measure the Dewalt DW779/780 to make sure you have the required depth to make it work. Looking at your table setup it looks like you will need to move it out away from the wall close to 12" if not more to fit the slider from Dewalt.
Measure the Bosch to see how much less depth it will take up, as it can be put up tight against the wall. If its going to be stationary, weight is of zero concern and I would go as far as to say if you want any equipment to be as accurate and repeatable as possible, NEVER move it.
All of the posts I have seen take their personal needs into account, but totally disregard the pics the OP posted. Apples and oranges comparisons imho.