My family and I are currently in the middle of "shifting" our life styles from 4 rental properties, 2 jobs, 3 cars, and multiple recreational toys; to no properties, 1 car, and no debt, and get out of the DC area.
We started the process 3 yrs ago and have the goal for both of us to be FIRE'd by the time we are 35. I am now 32 and quit my job 2 months ago to be a stay at home Dad, we are living in our last property (if anyone wants to buy a townhouse in MD/DC-area let me know) and have 1 car paid in full. The transition has been hard, but also rewarding. Our goal is to get to OH to be closer to family and raise our son away from the complex, busy, city life. We kind of have it lucky, since my family is already established in OH so building relationships is not much of a concern. The main concern is finding what to do with all our new-found time.
Back to your questions, as for challenges, when we moved to our current townhouse, we had hired a moving company (no idea who it was as I didn't do the hiring, but lets just say we went the cheapest route) to help us load and unload the truck. They never showed up due to the fact it snowed the night previous and god-forbid it snow in DC as EVERYTHING shuts down. So basically we had the truck for 24-hours and myself and my wife to move, oh and a 9-month old baby boy, who can carry small things and crawl, was a little hard to get him to understand directions. Bottom-line: spend some extra money and hire a reputable, well known moving company.
Unexpected downsides: (I know you asked about upsides, but not having a commute in DC and a job that you hate kinda covers them all). It def takes some adjusting to the stay-at-home life. Give yourself at least 2 weeks to 2 months if your raising a child, to truly feel like your didn't make the wrong decision. ;)
Sorry for the rambling, but hope you found something useful in there!