I think the SPX is interesting for anyone who wants LTE but doesn't require any fancy programs beyond the web browser.
But I also think that with the USB-C port, and not ditching the USB-A port, this is the best surface pro yet. I've been hanging on to a Surface 3 (non-pro) purely because of the USB charging, it's just so useful to be able to take a power brick and not worry about power. The SP7 should allow that, and I think with USB-C, that port will come in quite handy in the future too. Just need to keep an eye out for a USB-C to HDMI dongle. If it's compatible with other USB-C docks, then awesome.
Pricing wise, the SP7 with an i7 with 16gb ram and 256gb storage comes in at $1,500 which is pretty decent spec at that price point.
I'd wait for reviews though, I'm curious to see how the devices perform.