I have
a Samson C03, and I like it. It's a mid-sized condenser (19mm), with three patterns, bass roll off and pad.
I find it very easy to get a great sound from my old
Ibanez Concord acoustic guitar. I use the tried and true method of miking near where the neck meets the body for rhythm, and mike closer to the soundhole for any lead melodies.
I tried it on my guitar amp with different patterns and placement, but the SM57 blew it away for tone. The C03 sounded harsh, thin and brittle, while the SM57 was smooth and punchy.
Getting a good sound on my vocals is a lot more work (maybe singing lessons would help?). It doesn't like it when I scream at it too close, preferring that I give it at least four or five inches (any further and room noise becomes an issue). I A-B'd at my friend's house, comparing it with his SM57. The sound of the C03 was more detailed and brighter than the SM57, which is probably one the best cheapie vocal mikes for the studio.
I've also used it to record some native drums and it's fairly transparent for this application.
We did a small session with a two piece set (kick, snare, one crash, and hi hats), and it worked beautifully as a single overhead in omni mode with the bass roll off. It captured the sweet highs of the cymbals and the gentle smack of the brushes, the SM57 capturing the body of the snare. Don't get me wrong--this is no match for a matched pair of high end condensers, but it did the job.
Patterns: The cardiod pattern suits vocals with it's presence peak and proximity effect. In Omni mode, the peak is at a higher frequency and much more harsh on vocals, but is well suited to acoustic guitar. I haven't found any use for the bidirectional pattern yet, but it offers the flattest response of the three (no hyped frequencies) if you want a fairly uncoloured representation of the source sound, discounting the proximity effect.
Basically, for a hundred bills, you get a versatile condenser that will still be useful as an extra when you build your dream studio replete with handmade European microphones. Just don't put it in your published equipment list.