I am currently doing Leroy's program, this is my second time doing it in the past two years. I've done it on a bulk previously, and am currently doing it on my cut for contest prep. Some thoughts:
-It is an outstanding program IF you can tweak it properly for yourself. I think it's best to make an A-B-C workout and rotate the exercises, AND which body part goes first. Don't do the same workout all three days, that really limits your exercise choices and angles at which you hit the muscles.
-It IS an insane amount of volume, so you should NOT do it if it's your first full body 3x per week program. I built up my work capacity to be able to handle it. @Yogi_ is correct that if your diet, sleep, supplements, etc., are not all consistent and maximized, you shouldn't do this program. A good starting full body program would also be this one, it's the first one I did that got me to the point to be able to do Leroy's plan, Dan John's 10 Steps For Mass: https://www.t-nation.com/training/10-secrets-to-building-mass.
-If you do Leroy's plan, it takes a few weeks to learn how hard you can push it without killing yourself. I've found going to fail is not a good idea on this plan, CNS gets trashed and you can't recover properly in time to train the same muscle group again 2 days later. Learning what it feels like to get very close to fail without doing that last rep or two is where you want to be.
-In my opinion a full body plan is great for bulking if you have lots of quality food, and also don't over do it. You don't need a significant caloric surplus to gain mass. Your diet will control whether you bulk or not more than your training will.
-Plazma is a no brainer for this plan because of the high volume. I haven't, and wouldn't train without it.
Again I did Leroy's plan last year, and this year (not consecutively.) So far I've been doing it for about 11 weeks and am going to keep at it through my contest as it works best for my schedule. It's a great plan IF all the parameters are in place. Be sure to post back with any more questions!