I think x-stretch is a waste of time UNLESS you are a newbie to P90X and feel very sore after the workouts…then I would recommend it. If you are not painfully sore, I would swap it with something else or just take a rest day.
Yoga-x is a bit of a different story. First, you are not alone…I think most people feel it's too long. What worked for me is cutting it down to 45 minutes. I would only do the first section which was about 45-47 minutes long. I would then piggy back cardio-x on top of it. I would eliminate the cardio-x warm-up and yoga piece so I was only doing 22 minutes of cardio-x. At the end of the day, I felt like I had a great workout. I did this routine through 90 days.
I recommend sucking it up and do it through phase 1. If you are still not a fan of it, replace it with something (cardio-x is fine)….at least you tried. It sometimes grows on people after the first couple of times but you will not know that if you cut it out right away.
Personally, I think you would be fine cutting it out but I don't encourage it.