My brother has one of the Generacs & it works great but it's not necessary to spend that much to get the same result.
I bought the DuroMax XP12000EH dual fuel from Amazon ($1,100-ish) & it runs everything in my house. It has 30A & 50A plugs so you could use for a motorhome if needed. Dual fuel is great because you can store propane a long time without degrading like gas / diesel.
Since it's portable I also use it on jobsites & was able to write it off as a business expense.
I wouldn't risk not using an electrician to ensure everything is done to code. If something were to happen (injury or house burn down) your insurance probably wouldn't cover it. Also if you were to sell your house later that could be an issue in the home inspection.
There's a Generator Interlock Kit you'll need to meet code also. It ensures only 1 of the power sources can be on at a time (either the generator or the service feed) (
www.interlockkit.com)
Third thing you need is a generator cord / power inlet box. This is the one I used:
So far, everything works great & I'm really happy with the results. Glad to have that finally marked off the list.