I moved up from 6s+ to Xs MAX. I do like the bigger screen but I feel quality control is slightly less. I have to use the dongle for headset. Annoys the life out of me. The bezel scratches easily and starts to look ugly unless you have the silver one. and to top the dongle occasionally stops working and the phone needs a reboot.
however, the phone screen is nice and the browsing and usage capability is top notch. I would still upgrade.