I am about to assemble a MS microphone set for field recordings; after some testing and researching I have decided to go the Sennheiser route with a MKH 30 for the side, and either a MKH 8040 or 8050 as the mid channel.
At the moment I am bit stuck though in my decision between the cardioid and the hyper-cardioid: I am both into recording spot effects as well as ambiances - from what I have learned so far a cardioid in MS setup should give a more natural and consistent stereo image, hence it is recommended if the focus is more on stereo/ambience recordings. A hypercardioid though would offer a more focused mid channel apparently for anything that does not require a shotgun (and I would like to avoid a shotgun in a MS setup), which would be nice when recording spot sounds of course.
So, what to do? I can't afford all three mics yet, nor would I want to carry around a second mic for the mid channel with me in the field & having to open the Rycote everytime I need to replace the mid mic.
Best would be to do a shootout, but there's no real rental service around here where I live; maybe somebody can share his experience with hyper vs. cardioid in a MS setup?