We lived overseas a few years, but have returned to the USA as full time RVers.
We did quite a bit of comparison shopping. Items that were important to us:
* Driver License / Automobile registration ease
* Ability to scan mail
* Shred / Send mail costs
* Web access
Our first service while we were overseas was $10 Mailbox Rentals, Mail Forwarding, FREE Resident Agent, Notary - Las Vegas NV
We had decided on this one because we were Nevada residents when we left for overseas.
Our current service is St. Brendon's Isle https://www.sbimailservice.com/
Even though we don't stay near the mailbox their customer service and experience with residency / voting / jury duty has been top notch. Our mobile phones give us a number in the same area.
No state income taxi in either NV or FL (as well as some others)
There can be many hidden costs for mailing / monthly service / scanning / shredding / and access. Some even charge extra for picking up your mail on site. Compare carefully.
If I had to re-evaluate today I would still stay with St Brendon's Isle.