In the days when professional grade MF cameras represented a very substantial investment re-worked Kievs made sense for those on a budget or dipping their toe in the water. However they were a lottery with regards to both the quality of the product and the quality of service. I went down the Hartblei root in 2002 and had the camera modified with a Hasselblad acute matte focussing screen. I was lucky to pick up Schneider lenes for the Exakta 66 and multi coated Jena lenses at a reasonable price. The camera so far has been reliable and I have been lucky with my backs.
Would I go down the same route now? Probably not their is a lot to be said of the peace of mind resulting from the use of top class equipment.