Aside from my personal physical problems for which I was not prepared (altitude sickness), it was very, very beautiful. I'm from the East Coast, and it was refreshing to be totally alone (the isolation bit in the guide is true) in a landscape dominated by western pines and views of the desert and snow-capped peaks, all new to me. If you're not sensitive to altitude, I highly recommend this hike.
The spring was strong when I was there (late May), and was also my camp for the night. Each day's hike was around 5 hours (I hiked in at about 1pm and out at 11:30am the next day), so I needed no more than the 2 liters I was carrying each day...don't be scared off by that factor. The trail is not blazed, but the only time that was an issue for me was literally at the very beginning: at the trailhead there's a very clearly defined path that seems right but isn't, going into a bit of woods, and then there's the actual trail going in the other direction through a bit of dry rocky desert-ish terrain, sort of scratched out and barely visible from the parking area until you're on it for a few hundred yards. Luckily for me there was a local out there with some friends who pointed me in the right direction (after wandering around confusedly on small loop trails and through camp sites in the woods for about 45 minutes, until I went back to the parking area...duh.). Just follow the arrow to the trail like I didn't, and you should be fine once you're on it. Other than that, be aware to which of the two parking areas you are headed when you come to the gravel junction of Bristlecone Loop and Bonanza trails. I took the 2 mile or so way out which led me to the upper lot by the ski resort, which was not the lot where my pick-up ride was supposed to meet me...but never fear! I followed the road down a ways until I came to the appropriate place at the other end of the loop. THE END