Though this is an old thread, I figure I might as well add to the general topic here. The Rode NT1A is an amazing mic for the price and does very well on both vocals and acoustic guitar. Unfortunately, I sold mine a few months ago. As a replacement, I just got a Blue Spark. The Spark has a warmer sound on vocals than the NT1A in my opinion, but this may just be with my voice. I haven't tried it on any other sources yet. I'd say the Rode has a "crisper, clear" sound while the Blue has a "warmer, mellower" sound.
Just in case anyone is wondering about either of these mics, you can't go wrong with either. I haven't fallen in love with anything else in that price range, personally.