Most of my dblocks contain at most 5 or so attributes, so I haven't noticed any problem in that regards.
But I have noticed that complex dblocks, having 30 or more actions (guessing), take more computing power and use moderatlely more disk space then conventional blocks. In some extreme cases, I can toggle a dblock's visibility grip, and watch the block redraw entity by entity.
I have noticed too, that if you are editing dblocks all day long, that AutoCAD becomes sluggish to the point that I am waiting for it when I am opening a dblock for editing. The only remedy I have found thus far is exiting and restarting AutoCAD.
So I guess my answer to your question is yes, dblocks with lots of parameters and lots of actions are going to use more disk space. But the flip side to that issue is the efficiency your company gains by using dblocks vs. using conventional blocks, far outweighs the cost of disk space. Unless of course, disk space is very limited.