Sure, my main tool for field recording is an ORTF couple of MKH8040.
It depends on your use cases but the main things to think about for outside are wind protection, suspension, practicality. Taking these into consideration means additional costs, but i fear there is not much way around it. (Although, sacrificing some practicality, there are many cost efficient solutions).
My choice of a (lightweight) ORTF couple in a single zeppelin stems from how i like to practice field recording. That activity is mostly coupled with walking. I often move the mics during the recording; and even if they are on a tripod, i try many positions before settling on a spot for half an hour. Basically i want the experience of these tools to be as close as possible to using a handheld recorder, but with the utmost sound quality. (It still needs a bigger bag than a pocket, but the flexibility is there).
Then again, field recording is the foundation of my practice so the upfront cost of my latest setup was like a concert instrumentist buying an expensive handmade instrument from a luthier.
For the mics, it’s not easy for me to give advice except that i wouldn’t bother the hassle to bring “cheap” mics in the field when tiny electrets are mostly as good and way easier to carry. I would maybe just rent a great mic pair for a demanding project and hear if you find it’s worth using such mics (and subsequently maybe invest in them).
Oh, and imho the ORTF couple gives the closest result to “listening in person” (at least for me) and it is also the major reason for which i favor it over other techniques.
X-Y i find rather bland and only use it when strict mono compatibility is mandatory.
