Early February (before President's Day weekend) is really nice. The weather is usually great (better than home in PA, but maybe not warm enough for some to swim). The parks are not crowded and neither are the resorts. It is a really nice time for those who cannot handle the summer heat and crowds and can travel during the school year.
March was radically different because we traveled around St. Patrick's Day and it was the middle of spring break. Very, very crowded everywhere including the resort (CR). We did not get into our room until after 6:00 pm; we arrived at the hotel at 2:00. The weather was really nice on our trip; sunny, but chilly at night (a light jacket would suffice). IMHO - not the best time for a first WDW trip. We still had a great time, but the crowds were a bit overwhelming at times. We made the best of it, but prefer the slower seasons.