It was a great experience!
I always felt very safe with my guides. All three of them made sure there was head count and no one was left unaccounted for. It is definitely a difficult 4 day hike and trek overall with its ups and downs. Keep at your own pace. The 2nd day on Dead Woman´s Pass is definitely the hardest.
Bring and drink lots of water. It was helpful to take Diamox (altitude sickness pills) 3 days before the trek. I did not get altitude sickness. The food provided was great and very filling, but be careful as it can be traditional Peruvian food which can give your stomach some problems.
Weather conditions varied from day to day. Pack for sunny, rainy, and cold weather as you will need and use all of them. It was very helpful to hire an extra porter to carry my pack. The trail can be very steep and slippery, and not having a huge pack really helped my balance and made my experience way more safe and enjoyable.
Our tour guides were very knowledgable and great, our porters were hard working, and our cook was good too. This company has this trek down to a science. It is pretty well organized. However, ask lots of questions and confirm as things sometimes get miscommunicated between multiple offices and people with this large company.
Overall, a great experience!