For me, it's been mostly nightmares. I will say though that chat via a third-party messenger (e.g. WhatsApp, iMessage etc.) is significantly less frustrating than in-app or web chat, which frequently times out ("please respond within 30 seconds or we will consider your issue resolved" after having me wait for 15 minutes for an agent etc).

Same, though on spotty net, chat may not work or may not work well. Email is great when traveling.