Once, never again if it can be helped. Switched to FedEx and DHL (for high value) - both more affordable, smoother process, and cost effective with better quality service for my customers. CPC/USPS always preferred. Our experience with private couriers only occured when the package was outside the CPC/USPS parameters and used both for these parameters for around fifteen years.
Haven't shipped anything since the new changes took place but never experienced having to include any forms outside of an antique declaration that basically was me swearing my word that the item was antique, which it was. A couple of times for items valued over $2,500 my buyer had to supply personal information outside their postal address and phone number before the item could be delivered, everyone understood this was part of the legal process.
