I think that the DSB lenses are much like the earlier single-coated M42 mount DS lenses, only with the C/Y bayonet mount. I have had several DSB 50/1.9 lenses, and every one has had oily aperture blades. Watch for this, although in my experience, it did not affect the functionality of the lenses. I do find them a little finicky to focus, however. There are at least two versions of the DSB 28/2.8, one with a 55mm filter thread, which is not so great and also prone to oilyness, and an excellent (and very rare) version with a 58mm filter thread and an aspheric lens that is excellent and extraordinarily well-constructed. Good luck finding one, I wish that I had never sold mine because I have never seen another. There are also YUS (Yashica U S) lenses, which are similar or identical to the DSB lenses, I have found the YUS 135/2.8 to be a very nice lens and a good performer.
Often, you can find a Yashica FX-2 kit with three DSB or YUS lenses on ebay (the 50/1.9, the 28/2.8, and the DSB or YUS 135/135) on eBay for less than you will pay for the lenses separately.
The ML lenses have earned their good reputation. The ML 50/2 is one of my favorite lenses ever, it is a little gem and is one of the greatest bargains out there. The 50/1.7 is excellent as well, and the "kit" version, the 50/1.9, is also quite acceptable. I have also had good results from the ML Zoom 80~200/f4.
I have a short MC zoom that I have yet to try. The MC lenses are light-weight versions of the ML lenses, I believe.