Well, here my2 cents: European companies are fine, such as TNT or DHL, but for shipments to the States I would suggest either FedEx or UPS unless you would wish to ship heavy gear. I have used all of them, either way and never had any trouble, but I would surmise, that with US companies the release through customs might go more smoothly. Just a hunch.
TNT is now owned by Fedex. Been working with them on import and export for years. Never any issues. A little slower and cheaper but always smooth sailing.