Well, being that I have the give me's.. I went ahead and ordered. Mark, I think was his name, stated that having the multiangle tool wasn't a bad idea, even if adding the fixed angles because one could use it to check what the existing angle of the edge was.
Yes and no - that tool, particularly as it wears, develops slop in the degree-setting screw mechanism. It can get to where there's quite a mismatch between 3 degrees (fixed angle tool) and 3 degrees indicated on the multiangle tool.
This is not generally a problem if you're just using the DMT diamond stones for removing impact burrs - the stones don't really reset the edge at all. If you use the file insert, it's a different story. That file insert is coarser than most of the 2nd cut files the tuners around here use, and it will change the edge angles faster than it gets them sharp.
The other disadvantage of the FK/SKS multiangle tool is that it only holds the 75mm stones straight across. Your stones will develop cut marks and accelerated wear in a line across them.
The big advantage of a fixed guide is that it will hold files and stones at any cut angle. This is particularly useful for 2nd cut files (you turn the file in the holder until you get long shavings, smoothly, in a single pass) and for shaping sidewalls with a pansar file. It is also useful for minimising single-line wear on diamond stones.
Anyway - enough wet blanket from me - try to get a fixed angle guide before you wear out two blue stones. (Blue will be the one you most use - R and G are just polishing the work B does). You will probably have bought a separate sidewall cutter before then.