I have both Dakota (Bessey copy) and original Bessey K body (also Revo) clamps and have to say that whilst the Dakota are definitely not finished as well as the Bessey, for the price I think they are pretty good value. I am only a hobbyist but have used the Dakota many times without issue. I tend to buy clamps in pairs so the price difference quickly adds up! I bought the Dakota clamps in sets of 4 and they were certainly good value.
As an aside I have a couple of Bessey Kliklamps that are slipping on the serated rail after about 3 years of use - and that shouldn't happen! They will be going back...
The Bessey K body Revo are definitely a step up from the previous K body. They are v. substantial (and heavy!) but as I say - nothing wrong with the Dakota...
Hope that helps,
Regards,
Paul