B_hoves has hit the nail on the head regarding impedance.

IMHO it is much more difficult to get a nice sound using a mic than recording direct and this is because there are a lot more things that can go wrong using a mic. However, once you know what you are doing then the absolute best results can be had with a mic.

I normally use a Pod and I have been very happy with the results. it is posable to pick up a Pod 2 on ebay for very little cash and if you are serious about recording the guitar, it is a very good investment.