From my experience, you will feel more aggression, but you will also have more control over it, unless you let your e2 get out of control (in my experience when my e2 went up my ability to control anger went down).
Gains are, like others said, diet dependent. Keep calories at maintenance, and you will slowly but surely lose fat and gain strength and some mass. Up your calories significantly and you will be surprised at your delts and traps starting to pop like they never have before. You don't get any leaner this way.
Run a sound training program. I like full body 3x week, even while on test. 3 main compound movements with 1 or 2 isolations for lagging bodyparts per workout.
9 weeks into my first blast of 500mg test /week (also masteron for the last 2 weeks, 400 and 200 mg respectively) and those are my findings. Went from 220 to 240 (100kg to 110kg) with small amount of fat gain.
I am not a whole lot older than you so I am not going to tell you whether you should do this, but just stay on top of things. Monitor your bloodwork and heart function. Yes, everyone is talking about impotence, not being able to get it up, infertility, but cardiovascular stuff is, imho, what should be worrying you the most.
In only 45 days my hematocrit shot up from 0.47 to 0.53+. Having high blood pressure and breathing like a suffocating fish is not fun. I thought this hematocrit, hemoglobin stuff only happens to older guys, but boy was I wrong. High hematocrit means that your blood is thick. That can cause stroke, heart attack but it also makes your heart work harder and will accelerate left ventricular hypertrophy. Make sure these numbers don't get out of control and you shouldn't have a stroke. Also, make sure you control e2 as high e2= bloat = elevated blood pressure (again, a nice additional strain on your heart).
Just saying that this ain't protein powder which at worst might make you fart more.
