I'm not a pro, and in my humble opinion a will is fine for most. Some reasons where will's won't work,
-You have estranged kids.
-You have 'troublesome' people in your next of kin line.
-You have contested property in your name.
-You have a death benefit that's contestable.
-You have alot of debt (alot meaning it's a significant fraction of your estate, no one cares about a few bucks on a credit card).

I'm sure a pro could give you much better advice. Ask your insurance agent for some recommendations, they know who's who and what flies.