The biggest drawback to Texts not forwarding, is they do not store up for when you connect. My experience is they never arrive after you reconnect.

Let me reiterate on the IMS issue. When you return home, practice setting it up so that you are confident you understand the concept and procedure. When roaming overseas, when you move about, your roaming partners can change from country or region to region. This can alter your IMS functionality for free calling. It is dependent upon your voice line NOT having roaming service. For instance, let's say Vodafone is not a roaming partner in Spain where you begin your trip. You choose it for voice, and get free US calling. You then travel to Morocco, and Vodafone IS a roaming partner. You'll need to reconfigure to retain the free US calling. This is a hypothetical scenario, and is more likely if you choose an MVNO for non roaming partner, since the underlying carrier might not be known or consistent from country to country. Not a big deal, and once you get the hang of it, it only takes a minute or two to reconfigure. A glance at your top line Status Bar shows how it is set.