Typing this from my newly built PC Crate PC :)
Positives:
Overall, this is a quality build with good components, and as far as technical specs, this is a solid machine.
Even though I've done this before, having guidance (both written and chat) and a pre-planned guide helped me improve my airflow and cable management to a level that my previous build wasn't even close to.
My 5 stars is based off my happiness with the final build and the fast, friendly support.
Neutrals:
You probably ought to get a precision screwdriver. A medium sized screwdriver is included (a pleasant surprise), but that is only useful for the case screws, etc. The small screws on the motherboard are better serviced by a 3.0mm screwdriver you can get for a couple bucks.
Stay organized. Just good advice, but make sure you have a lot of room to lay everything out and take advantage of the order the guide says to open things so you don't have 10 kinds of screws to sort through.
Negatives:
It's not an all-in-one guide. Yes, it's significantly easier than doing it blindly yourself and it gives you a very solid roadmap, but you should expect to still do some research, read the manuals for the individual parts as you install them. Consider the manual like a highway map. You still need to look at the local maps for surface streets.
I didn't mind this, but if you're expecting this to just be like a lego set or IKEA furniture, it's gonna require just a little more digging to understand everything.