5th wheel vs Class A - which is better for US?

You already know the main issue you are worried about and that's getting around in the giant monster truck. Personally, I have a Class A DP and for the way I use it it's the best for me and my wife. If I was going to full time, I would likely consider a 5th wheel. The only draw back is I share your concern about the every day driving vehicle being the giant one ton dually truck. That's up to you to decide if it's workable or not.