Lizziguin, the lag could be a stuck horse somewhere in town. I started using Overwatch after I finished Great Bear and it made no difference if just one of those wild horses spawned in a rather very unfortunate place in town. I experienced a terrible lag which seemed to come from nowhere when I first started playing Great Bear, and it caused me some confusion as to why it was happening. I paused the game when the lag struck badly and searched around town and eventually found that a wild horse had spawned at the hospital behind a tree and a wall. I deleted the horse and the lag disappeared.
I use twallan`s Story progression nowadays and I think there is an option to limit the amount of wild horses in your world. I limited it down to two and the lag mostly stopped. I actually play with a no pets option for sim families as I find sim pets are more trouble than they are worth (but that`s just my personal opinion).
