I've steered clear of spell mods and major game changing mods. I think they would ultimately ruin the experience.
But things like cloaks, more lore friendly armor sets (Akaviri!) and weapons, bags, wearable lanterns (because lazy!), etc. are usually okie dokie. I've tried a few major graphic revisions, but I think I need to upgrade my rig before really using the punishing stuff. =\