For the most part, I tend only to master-build when going shotty (which is quite often). Since there aren't a lot of options when it comes to shotgun-oriented builds, Army of the Dead and Fireangel give you something very powerful to work toward. Of the two, MFa is my build of choice on Nightmare!, while MAD is often used on the easier difficulties (excepting defense-heavy challenges).
Otherwise, the only master-build I consider using is Ammochain, barring the occasional play of AoB or other unusual challenges. The Chained Court makes it way too easy to get agility mods, which corrects the one major flaw of a MAc build: lack of accuracy. I've mentioned multiple solutions in the past to change it up (such as to randomize the mods given, or randomize to include exotics as well) and I think it would make many people think twice before committing.
As for the others:
- Melee masters are obviously going to be used in a melee build and very rarely anything else.
- Gun Kata only comes in handy if you find a unique pistol or plenty of mods, otherwise you're lacking damage on the later floors. This is to say that leveling SoB, instead, is a less risky strategy but will assume a more experienced playstyle (as Gun Kata is great for dodging).
- That I don't pick Cateye is probably a personal preference more than anything, coming from whether or not I consider Intx2 a viable option. It has uses in certain cases, but EE -> EE -> Int -> Int only makes economic sense if you're playing a rapid-fire build (only the chaingun/plasma rifle would ever need +4-to-hit) and Ammochain lets you fire all you want into the dark anyway. If I wasn't expecting to level up a lot, I'd use it, but most games I can hit lvl12 without trying, and as high as 16 on UV games. Often Intuition tells you things that a veteran can intuit without its vision (go figure).
