Who is out there training IS/IP? Why are you still training IS/IP and what impact has it had on your training?
I took a long break from doing aikido-derived modern jujutsu in order to learn CIMA. Initially, that was for tactics and movement, but the longer I practice bagua, taiji, and xingyi the more I find it changing my approach to budo at a foundational level. I am so far off the reservation when it comes to how I approach locking/throwing at this point I am not sure someone watching me do applications would really say it is aikido or jujutsu. This has made it hard for me to go to a dojo and join in on aikido practice, but I have had lots of good discussions and individual training experiences with people who continue to practice aikido and are working on making internal ideas work in the context of aikido. Because starting CIMA involved me leaving my previous budo group, instead of it being an adjunct to my ongoing practice, I think my experience will be different from some others. I think the task of taking internal ideas and practicing them within the context of an existing practice, versus on their own, is very ambitious and challenging, and I am not sure I would be able to do well at both at the same time. It is hard enough to go from dojo to dojo within a single art, let alone incorporate a sophisticated practice of certain skills into an existing curriculum, especially if you are not the person defining it (e.g., average student at a school who is interested in the internal).
As to why -- the practice has fundamentally changed how I viewed martial arts and given me something that I feel has more depth and potential for exploration than the self-defence oriented judo/aikido/karate mix I had been practicing. I feel that committing to bagua, taiji, and xingyi has improved my practice considerably, and I was happy to put my jujutsu practice on pause and focus on learning instead of continuing to teach or trying to integrate basics from neijia into my jujutsu practice. Taking the time to learn some arts in a more focused manner was the right thing for me to do, but everyone will be different.