Reaching the lower Bushnell Lake is not difficult, as the trail is obvious to that point. At this elevation in the Sangres there is still substantial snow, more than I remember from the past and more than other reports note. The trail does wither at the lower lake, but can be followed up to the second small lake. It even continues to the upper lake, but is spotty as you near the lake. Some navigation skills and trail-picking is very necessary, especially just under the upper lake. It may, at least this year, be necessary to climb over or around huge mounds of snow in the trail, one was at least 10 feet high and much wider in diameter.
Other reports note that the upper Bushnell lake is larger, but this wasn't the case in 2007. The lower is significantly larger and deeper, perhaps due to the significant amount of snow unmelted at the upper lake. I highly recommend this hike. It is strenuous, but not as difficult as some others. The views of the Arkansas River valley to the north are breathtaking. There was significant traffic up to the lake for such a remote location, I know of 7 others that make the hike on July 1 alone.
If you want true remoteness, try the Stout Creek Trail to the Stout Creek Lakes, about 2 miles up Rainbow Trail. When my family and I hiked it, it didn't appear as if anyone had been up this year. We saw no one. It was a much harder, longer hike, however.