You should definitely give it a visit! The beauty of nature is something worth the visit, and Spiti is one of the best places to see that beauty! Many people claim that it is the best place on Earth, others claim that it is another world! Just by hearing this, I think you would want to go there already! And since you are going with family/friends, the visit is going to be much more fun and you will definitely have beautiful memories there. Even though going there might be time consuming and tiring because of the rough terrain, you will be rewarded and you will not regret it! Hope everything goes well!