Great Potsy24! Post some samples please. I think it would be hard to get a useable tone out of a acoustic guitar using the mxl r144, but let me hear what you did, perhaps it is better than I can think.
Any overall opinions on the mic?
My first impression was good. It seems to be well constructed, and comes with a good quality shock mount. The tone is what I was looking for, warm without high frequency hype. So far I have only recorded some acoustic guitar scratch tracks with it once, but I think it has a lot of potential for other situations.
Here are some samples of that recording. I miced a mid depth Ovation with an MXL R144 at the hole (6-8" away) and an MXL 993 sdc at the 12th fret (also 6-8" away). I was purposely going for a dark sound on the R144 here, but I think it would also be capable of a more balanced tone. My intention was to get the two extremes of the range of the guitar and blend them later. The preamps used for each mic were the front tube channels of a Presonus Firestudio Tube. The tube drive was about 1/2 way up, which adds a little warmth, but is almost not noticeable. These samples are the R144 alone, the 993 alone, and the two blended together. There is no compression/eq/effects on these tracks.