Her is my $0.02 worth.
Factory patch cables are great for many installations. They make for a professional look, and certainly make for a quicker install. And, as so many have stated, they are reliable.
Custom cables, when properly constructed, are also appropriate in many installations. I would always test any cable you make just to make sure.
I have a tough time understanding the resistance I see to custom cables. When properly constructed, they are every bit as reliable as their factory counterparts. If you take the time to understand the cabling standards, follow recommended assembly procedures, use quality materials, (and are not color blind), there is no reason to discount making your own cables when the situation warrants.
As a matter of practice, I always use boots when constructing my own cables. I like the look, and it matches the factory cables they are neighbored with. I always double-check wire placement in the connector before the crimp. In carpentry you measure twice, cut once. In cabling, look twice, crimp once.
The connector/crimp tool you are looking at seems like it would help in quick cable assembly. You might try making several cables of differing lengths and test each one with a quality certification tool. If they all pass…
I say go for it.