I think most of the "stand-by" (= automatic) generators come with an automatic safety switch. You'd almost have to have it, because if power came back on, I'm sure you'd fry your generator without it....right?

Built-in, stand-by (= automatic) generators are becoming very popular in this part of the country also. If you have an all electric heated house, you might have a problem?

Edit...
Also, though it's easy for me to spend someone else's money, I'd always buy the largest model available of the type you're interested in. Not saying you have to end up with a Cat V-16 or something, but the extra $$ for a larger Generac or whatever means you can expand later. Does ANYONE here have less electric in their house than they did 20 yrs ago? I'd suspect that we're all hoping for 20 yr + life from stand-bys.