Still undecided SP4 versus SB after 3 months

Hoping to order one next week to be my new general computer for the next 4-6 years (I kept my last clunky workstation computer for 9 years). I will not be using any external monitor, and my use case is homeschooling my kids requiring numerous apps, photography, general office apps, and occasional 3d modeling or video editing. I already have access to an Amazon fire hdx 8.9" tablet, which is currently my favorite device and I've moved away from performing most computer tasks in desktop to tablet form. Still, Amazon devices are android and therefore limited...the hardware is also too underpowered....not to mention accessing websites can kill the eyes with its 8.9" small size. I do have access to a monster workstation when needed, but I hope that will be rare event after getting a surface...

From what I can tell, the SB has the advantages of: - Larger size, but not by enough to make much difference except when viewing video or using it in tablet mode at near distance. I do have older eyes, so I am paying attention to additional screen size. I can't no longer text on cell phones as well as I used to when wearing my regular distance glasses (both near and far sighted).. - Be useful as a good portable whiteboard or video display during class sessions - Builtin SD Card slot which is good for cameras and 3D printers - CUDA acceleration for some apps - Longer battery life, but only when the display is disconnected (important to me, but I'm primarily a tablet user...I'd probable end up us in the SB with display turned around and keyboard disabled most of the time. - Ability to run longer periods without thermal throttling or exceeding system power design limits, useful for video or 3d modeling rendering. - have less risk of damage, the sp4 seems to be more fragile from what I can read here in reddit and on Amazon - has a much better keyboard and mouse, important to me as I'm a crazy fast typist...except that I don't type that much on a daily basis anymore.

However, the SP4 with i7 CPU and iris graphics seems to: - Have a higher quality lower brightness screen (from what I can see while testing at best buy). I prefer to run displays normally between 10-40% brightness to avoid blinding myself after prolonged use, especially when moving in and out of rooms with varying ambient brightness. - Be easier to grade and annotate student homework in pdf format while moving since I won't have to deal with unlatching the tablet - Be easier to move around house, to treadmill, couch, or bring into bed. - Deliver most of the benefits of the SB discrete GPU without having the bugs associated with video card driver switching. And, would be faster for many apps since it beats out the built-in gpu in the SB. - Has the awesome kickstand, important since I'm finicky on display viewing angles. The SB may not bend back enough for my normal usage, unless rotated backwards..

I guess ideally, I'd get both...but will have to choose one for the time being... decision somewhat depends on how many issues associated with using SB in tablet mode more often than not..although I really don't want to pay premium for SB discrete GPU over SP4 i7. Will be getting 512GB storage.