“I thought every low testosterone guy that went on HRT (TRT) felt great afterwards?”
No way is all I have to say. Many men actually feel worse on testosterone therapy and then feel better when they quit, and below I am going to give you a couple of interesting examples of that. Let’s start with a story from the Peak Testosterone Forum: 
Case Study #1. “So on Tuesday I ran some labs. My total T came back at 492ng/dl and free T came back at 13.1 pg/ml. My pre TRT levels were around 370-400. While being on TRT I lost around 50lbs and also ate a lot better I still have about 20lbs to lose so I still think there will be some improvements on levels. While on TRT I never felt right, but since quitting I realized some of the things TRT took away from me as well. One , a lot more mellow off it. I actually feel tired now around 10-11pm instead of a somewhat wired feel. Orgasms are also much more intense off the testosterone. Just wanted to give some insight that it is possible to come off TRT after years and have your levels come back even higher than before. I also will now focus on some of the things on this site to help out on the natural level.”
CAUTION: His estradiol is low enough to potentially experience some bone loss. Hopefully, his doctor was monitoring it. If his estradiol indeed stayed low, then this could be a reason to go on testosterone therapy.
Basically, he found that he was trading some anxiety and restlessness – a “roller coaster” as he put it later in the thread – for improvements in body composition and weight loss. And, in the end, he decided TRT was simply not worth it. Some might say, “Of course, he did not do well, because he did not boost his testosterone enough to feel better.” Unfortunately, he had been on testosterone cypionate and got his testosterone up into the 700’s with no improvement.
Another unusual thing that about his story is that he felt better with testosterone in the upper 300’s. This is well below the average level. See my article called Normal Male Testosterone Levels by Age for more information. This is yet another example as to how testosterone is very individual. Some men, like myself, seem to need higher levels. I did horribly, for example, in the 300’s. However, one clearly cannot assume that this is the case for all guys out there.
Case Study #2. Another of our long-time posters was a young guy who struggled with erectile dysfunction while on TRT. He finally decided to quit cold turkey and was very glad he did. Here is what he wrote in one post:
“Hi all just want to give a little update on my situation… I go to endo in two weeks.. I am 16 weeks off testosterone today…I have had sex everyday for 60 days now… at least once a day..sometimes twice a day….No E.D. whatsoever.. the only problem I am having is sometimes when I am on top my erections are weak and not strong .. but they are still strong enough for penetration… I weigh 230 pounds and im 5’9… if I were to lose 20-30 pounds would this harden erections up?? I remember when I weighed 200 lbs they were hard…im 36 years old.” 
His case is interesting, because he was struggling in the bedroom and his doctors just put him on TRT and gave him 5 mg of Cialis even though he was in his 30’s! Unfortunately, this is the typical solution from Western medicine: throw a bunch of pharmaceuticals at the problem. Usually, young men in their 20’s and 30’s can easily fix their erectile issues with lifestyle changes such as those I mention in this page on Improving Your Erectile Strength. In fact, that he is he very overweight and could probably lose 70+ pounds. Losing this much weight would very likely end up doubling his testosterone levels, something I document in my page on Testosterone and Weight Loss.
FINAL COMMENTS: Notice that both of these were young men who did well with testosterone levels below the average for their age.
Does this mean that no one should ever go on HRT? Of course not! The Peak Testosterone Forum has many examples of men who have, like myself, had a miraculously positive experience with HRT. However, these two examples show that, clearly, men are sometimes put on HRT when they shouldn’t be. This is not necessarily an indictment of doctors, because there are many other conditions that lead to hypogonadal-type symptoms. I outline many of these common conditions in my Peak Testosterone Program page and it includes issues such as low cortisol, high cortisol, hypothyroidism, sleep disorders and many more. I urge anyone that is “just not feeling right” to scan through these pages.
One other important discussion point that many doctors leave out is that there are other common non-TRT options out there now for men who feel they need to boost their testosterone. These don’t have quite the success rate of standard testosterone therapy in my opinoin but are definitely worth condiering: HCG Monotherapy and Clomid.