My view on the matter, custom content/all objects/avatars (sims) and Lag:
As one mentioned in responds, adding more to the game, I agree, however.. think on this, and in long ago past...
The first "outside" theme lots were not for "pretty", but to help reduce lag.
Every wall, window, door........ objects, then add a full house of avatars (sims) all together contribute to the Lag issues. Huge reduction of lag was found on full lots with outside themes (one floor homes, less walls/windows/doors needed)... much less floor tiles... on and on...
If you play multi avatars(sims), watch the differences. If it is NOT a game itself issue (with codes etc problems), but lot issues (many times usually), you can view how one lot drags frame to frame, while another lot seems to flow just fine (watch with comparable amount of visitors). After seeing the difference, look around the two lots. Usually you'll find on the more laggy lot, ALOT of un-needed objects. Usually much more built up in housing, pools, etc. Yes, also finding alot of custom content objects. I do not believe it's the custom content objects itself, but all objects in combination, and our avatars (sims) do count on that lot.
My suggestion, as owners of business lots, skills/money category mainly (most visited in large numbers)... layout your lot in best greening abilty for your guests, along with needed objects pertaining to your category, theme. Allow your members (roomies) to maybe set out a couple of personal items to express themselves if you desire... but remind them, they do have other sims that one could very well hold a lot (home) of their own to set out their "pretty/amazing/etc" objects, so to lessen, or as preventive lag on your business lot (most are very understanding to this request). I really believe with this positive action, you'll see a huge difference in performance on your lots.