The combination of price and absence of user upgradable M.2 SSD drives make this product un-viable in my opinion. The current price is fine if I could upgrade the drive later. Non-upgrade-able SSD would be acceptable if the price for larger drives was more reasonable.
If SSD could be upgraded buying a i5/i7 would have offered amazing upgrade paths down the road. This machine misses the mark IMHO but not by much.
You can upgrade the drive, externally through tb3. There will be tb3 enclosures that exactly match the mini’s size (historically there always have been) and it won’t even look weird. I did that on a previous mini (firewire).
Having said that, I’m still going to get one with 512gb ssd, because I just want everything neatly in one box.