The main problem with HRT is finding a doc who knows what they're doing. Once you have that obstacle out of the way, it's a matter of adjusting dosages until everything is right. This process can take awhile since everyone responds differently.
For example, "estrogen dominance" (high ratio of E to T) is a lot more common in older and heavier (obese) men. They tend to convert exogeneous T (gels, injections, etc) into estrogen more easily than younger men. For them, being on an aromatase inhibitor (usually Arimidex), or estrogen management in general becomes very important and can be tricky to manage. You need E to feel good an function properly, but too much of it is dangerous to your prostate and can make you feel like shit.
Aside from that, periodic blood testing is needed and you have to ask yourself if you're ready to commit yourself to a lifelong form of treatment? HRT should be a last resort after all attempts to fix your current system have failed.
For most men, HRT improves their quality of life, but a lot of people agree that even proper HRT is not as good as an "all natural" system that is properly working. As Swale once said, "You can't trick the body. It is smarter than you."
Sonny