My sniper class is actually one of the few classes that I run CB on and it's mainly because of the not showing my name effect. I also run it on my anti-Lodestar class. I hardly ever breakout either of them because some guy with a TF is just too good to beat without it and I run into TF users all the time. I suppose that I can thank Marksman for giving me the training needed to have the map awareness to make TFs a non-issue.
Not from what I can tell. I used to be able to see guys inside buildings with Marksman if they got anywhere near a window. They didn't have to be in a window. Just near it and I could watch their name move as they went deeper into the building. On a TFs best day you might get lucky enough to catch someones diamond through a wall if you happend to be at the right angle but that was supposedly patched. If you think about it, it's actually a nerfed version of Marksman because the TF does have the periphial view cut off and Markman didn't have any view constraints.
I'd say it should have no mini map when scoped in and some recoil but I'm not sure how much. Probably 5% and have Dual Band and Variable Zoom a little less or whatever. Then it makes the other attachments a viable alternative as some of them are just a waste of space, like grip.
Where did you get information that the MMS decreases centrespeed? It doesn't but it is perhaps the slight increase zoom that might give this impression. Zoom level is 1.103 with a FoV of 60. That's the information I have.