I have a few I shared. I don't bother most of the time. Most players have this ... "stigma"... about "sharing" sims with CC, and all my sims use CC. It's like if you share something with CC you're the devil incarnate and should be burned alive.
Also, most of my custom sims start out from someone else's sims. I search the gallery for someone I like, like Emma Watson, look for someone's creation that's the closest, and I modify it and tweak it to look better.
Other players don't like it when you share someone else's work, even if you modify it and it looks nothing like the original.
The 200 limit on the number of sims appears to be somewhat fluid. I believe that the limit is there to help keep people from overloading their games but you can run a lot more sims if you pay attention to what the game is doing and what kind of lag you get and can tolerate. As long as the game runs smoothly and you don't get crashes, you're probably ok running more than 200 sims but that will vary depending on what hardware you have and how you play.
The number of sims you can successfully have in your game is really dependent on the computer hardware you are running the game on. People with high end computers with faster processors, lots of RAM and high end graphics cards can run the game with a lot more sims than those with low end machines.
The amount of cc you have and what it is also will impact the game performance. If you have a lot of high poly cc, the game will lag a lot more than a game without it. This is where the quality of your graphics card and how much RAM it has comes in. CC hair is a very good example. Most cc hair is moderate to high poly and when you have a lot of sims using it together in one place in the game , you generally see a lot more lag in the video performance and it can cause your game to crash a lot more.
I have a pretty good desktop and currently have around 425 played sims in my main save. I do use cc but not much and no cc hair or high poly objects. I haven't had a crash in ages but at times my game does bog down but runs pretty well for the most part. I still get a lot of NPCs but I do see a lot of my sims out and about in all the worlds. But my game would probably cause a low end laptop to choke and cry uncle.
In a nutshell, each player just has to experiment and figure out what their particular setup can handle and adjust their play style to how the game performs.
Hope this helps.
