Honestly if you are looking for customization and future-proofing, this isn't the product for you. I had a custom built PC for years, and now working full time in IT had enough coming home to a custom rig I'd buy new parts for/have to toy with. I wanted something also far more compact than one could build while maintaining some level of upgradability (video card, SSD, possibly ram) to get my money's worth until such time I'd have to do a full upgrade. The unit went on sale for $100 less at BB so I snagged it after reading up on the cost of the sum of it's parts vs purchase price.
Asus G20CB - Core i7 6700, Nvidia GTX980, 16GB Ram, 256GB SK Hynix SSD, 1TB Samsung SSD.