Things are not as bad as they used to be. Normally, things just work now. If you do it per the normal/recommended way of doing things.
What is still abundant is the marketing techniques used to mislead, confuse and sometimes simply lie to the customer. SATA6Gbps for mechanical harddrives is not useful at all; it would be like driving a cargo truck on a highway where you can drive 600km/h; but you can only do 100 barely. And HDDs are like cargo trucks: slow to accelerate and decelerate, but once they take up speed they are okay.
If you really want performance, using an SSD as system disk is highly recommended. Especially on an expensive workstation. You can also wait for the newer generation of SSDs, which should arrive by Christmas this year. They should really be able to make use of SATA 6Gbps, so your ports are still useful.