I have been using them for years. Got in near the start of them I think. Easy to use and works fine for me. I have only one payment, one return, and maybe ten shipping ones. First class, priority,media each get one for fee ship and one for calculated and then there is a few one offs like ground shipping only or the like. You still input weight and dimensions. One nice advantage is you can bulk change some thing like handling time or international options with a few clicks by updating your policies.
Would have to say its easier. I know when working on listings I buzz through the policy section pretty fast