I noticed the same thing several years ago, when I replaced my old big bear with a Cat 500. It wasn't just wider, it was taller. And yes, it did feel tippier than the bear. It also rode sooo much smoother, and could handle rough ground that would leave the bear high centered.

You get used to it after a while. Change of shock settings, change of tires both help. Mainly, it's getting used to a IRS quad with high ground clearance, they just feel different. I've taken my Cat to places that the old bear couldn't have possibly managed, including off camber stuff.