When the iPhones were announced last year I had decided before the event that I wasn't upgrading, and for a while after the event I held out - until I found out I could get a real dual sim iPhone XS Max from Hong Kong, which means no restrictions or modifications to iOS, and real dual sim capabilities. When it dropped in price a little I caved and flexed my credit card. (For the curious I found the iPhone on eBay from a UK seller - I picked the seller with the highest ratings and everything went smoothly.)
Why dual sim? For many people this is unnecessary, in my case I am fortunate enough to have both my work mobile number and my personal mobile number on one sim, however I have an older personal number, and my UK number which I still receive messages on - and in the case of the UK sim I often use it when travelling (both to the UK and other places as the provider, Three, offer good travel packages). Some people have separate work and personal sims, and it's definitely nice to have the option of switching sims when travelling if only to get a cheaper data plan, whilst being able to keep your regular number to receive incoming calls or messages.
So, it's pretty simple to use and works precisely as documented by Apple, you pop out the sim tray, the sim on the back is held in with a small plastic spring and the one on the front is held in with gravity. Once you put the sims in you get asked how you want to use them, and off you go. I don't have an e-sim option at all, which means if I travel somewhere and want a local sim I'll have to buy it first. That said, in most countries there's only one e-sim provider and they're usually not the cheapest so I probably wouldn't use them anyway.
The only thing missing from this setup is the ability to use both numbers with iMessage - unfortunately you're limited to using the primary number with FaceTime and iMessage. However in my case I chose to use my email address as my primary contact information for iMessage a long time ago which alleviates that issue quite nicely!
Now to the Max itself. I was previously a member of the of the Plus club (as it was christened by the fabulous hosts of Connected. In 2017 I thought that the X would be perfect for me and it was indeed an excellent device - but I really do like the bigger screen! With the Max I caved to the trends and bought a pop socket as recommended on Cortex - and my little finger is very thankful for this as I have previously rested the iPhone on that finger.
The very exciting part of the S and R series of iPhones of course is the ability to read NFC tags without opening an app first - this is going to be a great automation possibility, simply because I can be prompted to run automations when I put my iPhone down in specific places such as by my bed. I'm very sure app developers are going to be taking advantage of this! Launch Center Pro has already updated to support this ability and it's coming in handy - for everything from triggering shortcuts to accessing OmniFocus perspectives.
The one thing I had not realised I was missing was battery life. With my X I needed to charge the device most evenings when getting home from work, now I can make it until bedtime and I often have about 40% battery remaining (unless I play Pokémon Go, which requires a battery pack on any device). I've already seen how useful this is on trips - while I always have a battery pack handy it's nice not to need it, or at least to not be tethered to it. I won't be travelling long haul until I visit Seattle for PodCon later this month - but I suspect with low power mode I would be able to get by with just a small battery pack if I choose to do so.
All in all, I'm very happy with the Xs Max and don't regret getting it at all. Was my X good? Definitely! And I wouldn't recommend this move to most people, but for me it definitely resulted in benefits so was definitely worth it.