We used Escapees RV Club's mail forwarding service for 20 years without any issues - Livingston, Texas. When we first began full-timing we didn't have a computer or a cell phone so back then our mail was very important to receive in a timely matter...and it was...usually about 2-3 days sent Priority to a small town post office c/o General Delivery. It worked well.
Nowadays, you can have your bills Auto Pay so you don't have to worry about getting mail on time. However, you still need an address for your license, vehicle registrations, insurance, voting, etc. A mail forwarding service will give you that address.