I have 2 of these units in studio use, I've used plugin recreations of Pultec EQs for a long time, and also several other hardware versions. These are as good as any, and better than many. When one considers the price, it's a no brainer!
Build quality is very good. The knobs, switches and pots all feel reasurringly smooth and solid. They are very quiet in operation, negligible hiss or hum, and don't get too hot. The 2 units I have are fairly evenly matched and could be used as a stereo pair. Not only do they sound nice, but working with hardware units in the physical realm rather than with software is very pleasurable.
The Klark Teknik EQP-KTs are one of many "character" EQ units based on old classic Pultec units. As such they are perhaps more useful for broad tone shaping than precision surgical tasks. In use the sound of the EQP-KT is smooth and musical, it's easy to perform the classic low end "Pultec trick". the HF bands are clear, more forward than some similar units/plugins but not harsh. These KTs are perhaps not as "characterful" as some other Pultec clones and plugins, but that's not necessarily a bad thing, and one can always drive them a bit harder if you want to acheive that sound.
These might not be boutique recreations of a piece of classic gear, but they are well made, sound good, and can easily do all the jobs one expects of a Pultec style EQ. The immediacy of having physical control ia great, especially when tracking.
I'm considering buying some more!