^^^^I made the mistake of upsizing the SSD to the 1GB level. I say mistake because it is sitting in my machine unused. I plan never to use it due to the restrictions imposed by the T2. I have six other SSDs (Two on a Syba I/O Crest and four on a Highpoint 7103) in my machine.
I went with 2 TB, with this reasoning. First, while I believe I've read how to boot to other other internal storage, I didn't want to bet the farm on it, and also I don't need a ton of storage from the start, so I'd just as soon wait, take the time, upgrade any other storage down the road.
But 256 GB standard is just too pathetic, sad they even had this as the base. And I use a lot of audio plugs, which don't live happily on anything other than the boot drive (yes, you can move sample libraries elsewhere, etc, I already do). So I know from experience that while 1 TB may be good enough for a boot drive, if I want to live with it a bit as primary storage, I'll bump my head on that roof way right away. So, what the heck, another $400 for the 2 TB, and maybe there will be more choices by the time I get to PCI-based storage.
So, you could say I paid $800 when I could have put that towards bigger faster PCI storage. But I was never going to buy with the base 256 GB SSD, I would have felt I was buying something wounded. From my point of view, I stretched $400 for something I can use for a while at least. I'm not cranking through video, storage isn't going to be my bottle neck anyway. I simply don't need the 8 TB at super high rates people are drooling over. My bottle neck is cpu/cores.