I have the code and it offers many more USB ports on the i/o. I believe the hero has less USB ports but it does have a DP and ps2 port which the code does not. Plus they are aesthetically different.
Yes, I have built many computers. Probably in the mid 100s as far as quantity.
My main computer (in its current iteration):
Intel 8700K @ 5.1GHz
ASUS Maximus Code Motherboard
32GB (4x8GB) Trident Z @ 3466GHz
NZXT X62 Kraken AIO
2TB Nvme
3TB (3X1TB) SSD in Raid 0
ASUS STRIX 1080 Ti in SLI
EVGA P2 1200W PSU
Fractal Design R6 Case
Plus a lot of LL120/140 fans.
I would purchase anything used if it works, the price is right and I have a need/want for it. All my computers are made from used hardware, most my furniture is repurposed and all my clothes are preloved, albeit tailored a bit.
I would recommend swapping out the 1660 Ti for a 1660 Super. Roughly the same performance for cheaper. And maybe consider getting a better PSU with a longer warranty. Something you can re-use in a build a few years down the line. Reference this PSU Tier List for ideas.
I would recommend the ASUS graphics card because I've always had a good experience with their product line. But realistically it comes down to what card you think looks best because they should both perform roughly the same.