I went on this trip along with a couple of friends towards the end of May. We had limited time, but were interested in doing a peak, and this seemed to be one of the less expensive and fairly achievable trips that we could find. Given our lack of mountaineering experience, we thought it would be a good idea to have a guide with us (which it was)! Physically, it was not too challenging, so I think if you are in pretty decent shape you should be able to make it to the top. That said, how your body will react at higher altitude can vary and is largely dependent on genetics (sorry for rambling on).
The location, Langtang Valley, is absolutely spectacular, it is a very surreal experience being surrounded by 6000 and 7000 meter peaks. There is also quite large variation in landscape, flora and fauna, as you gradually move to higher altitude.
Mountain Monarch does a great job providing all the necessary equipment for the journey. Pretty much all needs that you have can be provided, and they are extremely professional. For this particular trip, I think it was a good idea to have a lot of help, as we were all fairly new to peak climbing. The food in Nepal is also great, and healthy as well! I would like to thank the whole crew and our guide Ngima for the trip, it was a fantastic time which I really appreciated. Would definitely recommend this trip if you have the time and finance!