For Rent is, in my opinion, dangerously bugged. I do not make or use any residential rental lots. I have started a brand new game and deleted every native EA residential rental lot, leaving them all blank, to avoid game breaking bugs related to hard limits on total game size. Refer to this thread for more info related to this dangerous bug: https://answers.ea.com/t5/Bug-Reports/OPEN-Houses-Lots-disappear-Error-800-or-801/td-p/4620279
I love the furniture style that comes with the For Rent expansion, and the world is pretty to visit, so I do not wish to disable the expansion. But I never play the world lots for my sim to live in, as their home lot. I do not trust that world for anything but visiting.
Horse Ranch has become my favorite world and my primary sims live on the largest lot in that world. I also enjoy the furniture style and build mode items that come with that expansion. The game play (everything to do with horses) is wonderful and I love the mini sheep and goats. I also enjoy the CAS items.
I never found Horse Ranch to be buggy, at all, when it first came out. Since then some of the base game updates have bugged a couple things for some players, but that is not the fault of the expansion. And I think the mods I use must be fixing things in my game, because I have not had problems.
My previous favorite world, the one that came with Cottage Living, was more bugged than any of the lots in the Horse Ranch world, which is why I eventually decided to just move my sims to the world from Horse Ranch, and I have most heavily populated that world with my favorite non-played sims. I have also renovated the recreation lots in the world.
I see no downside to Horse Ranch, but I would advise anyone who has not already purchased For Rent to avoid that expansion until the game breaking bugs have been fixed.