The second adapter is very similar to what I had on mine: works the same way, only real difference is mine had passages for an oil cooler, and a temperature/pressure sending unit. The lower unit has been for sale since I got my CB750K, back in 2006 -- which is when I started looking for mod-parts. If I were in the position of having a CB again, I'd buy that adapter in a second -- I loved being able to use a spin-on filter, and I could buy the different grades of filter, to go with my synthetic oil, allowing me to go 5,000-7,000 miles between changes.
Anyway, the lower unit is reliable, simple, and virtually foolproof. You will only need to change out the large O-ring once in a very long while, maybe every five years, to be safe. Once the adapter is tightened into place, the large O-ring will have very little surface area exposed to either air, or oil. The real advantage is not so much the time savings, and the ease of changing the filter out, but rather the freedom to choose different filter grades, and types, along with the back-flow valve, which doesn't exist in the OEM setup.
You will need to carefully measure filter heights, as it will shift it forward, with the adapter -- closer to the front tire. Different filters will have different heights, widths, and threads -- keep a list of car models, if you can, as that is another way to know which filters will fit, besides the specific model number. If you need a filter, and they don't have
Acme Model XYZ, tell them the car model, and they'll come back with
Delta Model FGH, which fits 'that type of car'... Cheers!
1979 CB750K (sold, 2012, but not forgotten)
1983 Kawasaki 440 LTD Belt Drive (sold, 2011)
1993 Kawasaki Voyager XII