I'm by no means pro, but I've done it going M/S stereo. Got good results.

MS Stereo Basics | Sound Notes | Sound Devices, LLC

So you aren't reamping through a guitar amp - just trying to get "room sound." For this to make sense, your speaker, room, mic, preamp chain has to be better than your reverb unit. The weak link here is the room. If you have even really good reverb plugins or outboard units, you have to have a really great room. No way this would work for me. As far as how to do it, I'd be more inclined to go for techniques with a more pronounced stereo effect - ortf, ab.

Bob, I'm not trying to get the "room sound" at all. Rather, recording real air being pushed - which sounds different from recording straight into a line input.

I have heard of this being done before, back a few years on this very forum. I have yet to try it though... wish I could comment on its effectiveness, though there are so many variables. Try it and report back once you've experimented a bit.

Strangely enough I have just done this when re-recording a bass part. I plugged straight into the back of one of my HS80's and mic'd up with an AKG D112 and a Rode NT5. The Rode sounded much better, which initially was a surprise to me, but then I realised that the NT5 was probably more suited to the frequencies that an HS80 produces. So in answer to your question I would try Rode NT5's in a stereo situation although I suspect a pair of the the ubiquitous SM57's would make a decent job of it too.

I did it (albeit in mono) once to get some "room" on rhythm guitars. I put the mic across the room facing a reflective wall. That way the mic only got the bounce and no direct sound. One pass for each rhythm guitar (2 of them) gave me a nice stereo effect and some "real life sound" to the rhythm section.

I say stop worrying and start experimenting! All you need is a quiet room so the dishwasher or lawnmower won't get into the mic(s)!

Thanks for your answers.

I'll experiment with this as much as I can. Eventually it comes down to your choice of microphones, miking technique and the sound of your room. Next time I'll try it with two SM57's.