I found quite a lot of mods, even those from popular sites contain a multitude of errors, and this has been a major factor of errors while saving, CTDs, black textures and slow-downs. I'm now quite careful which mods I install.
Anach, if you have the time and inclination, could you describe the types of errors you've found? Not in any great detail or necessarily naming the mods, just in point form, perhaps in a new thread.
This could serve as a handy "things to watch out for" checklist for new Sims modders such as myself. It seems every game develops some modding folklore concerning potential pitfalls to avoid.
Thanks!