A few things to start off with. If you are looking for something "scandalous" or "dirt", you will not find it in this post. I consider Rinpoche to be a fine teacher and very authoritative. I will not speak poorly of him in any way. Also, if you are looking for "secrets" it will not be found in this post either. Furthermore, this post will be really vague because the only times I have really interacted with Rinpoche have been either via e-mail or at teachings. Lastly, much like I am not an authority on the Dharma I am not an authority on Rinpoche. Please keep that in mind.
I have been attending teachings given by Rinpoche since around 2008. If I had to use one word to sum up my interactions with him, it would be "traditional". Though he is most definitely not "New Age", he is also not a "New Buddhist" in the sense of the more atheistic brands of Buddhist. In the relative sense(and he is always quite careful to differentiate between relative and absolute truth) ghosts are ghosts and spirits are spirits.
Of the teachings I have attended, there are some things that I think I can say. Most of the texts that he presents are very, very short(the Green Tara practice you can find on tersar.org is a great example). Because his teachings tend to be about one or two days this means that you get a lot of information that might not be directly connected to what you planned for. For example, during a recent Phowa teaching he gave us a very good teaching(but not a full practice) on how Dream Yoga works, including a practice on how to sleep without medication that is really quite useful(I won't give details because samaya but I'm sure if you were to ask him about it he would share it).
Rinpoche tends to have two types of teachings. The first(and the ones I usually attend) I call the "householder teachings", meaning that they are usually around one to three days long. The other are retreats which last at least one to two weeks to upwards of a month. I hope someday to be able to do the longer retreats but for now as I have very limited vacation time I do the teachings and try to improve as best as I can.
Usually the way that I interact with Rinpoche is via e-mail. I've found that if you take the time to really edit your message down to its essence that you will be rewarded with a good response(I'll spend about four minutes typing an e-mail and about 30 minutes paring it down).
The Sangha that surrounds him are very good people and extremely dedicated to the Dharma and to Rinpoche. As far as I know they are technically householders but the ones I have met are as dedicated as any fully ordained monk.
IN THIS BOOK IT IS SPOKEN OF THE SEPHIROTH & THE PATHS, OF SPIRITS & CONJURATIONS, OF GODS, SPHERES, PLANES & MANY OTHER THINGS WHICH MAY OR MAY NOT EXIST. IT IS IMMATERIAL WHETHER THEY EXIST OR NOT. BY DOING CERTAIN THINGS CERTAIN RESULTS FOLLOW; STUDENTS ARE MOST EARNESTLY WARNED AGAINST ATTRIBUTING OBJECTIVE REALITY OR PHILOSOPHICAL VALIDITY TO ANY OF THEM.
Wagner, Eric; Wilson, Robert Anton (2004-12-01). An Insider's Guide to Robert Anton Wilson (Kindle Locations 1626-1629). New Falcon Publications. Kindle Edition., quoting from Alister Crowley