For me building muscle is more challenging. I don't have problems when it comes to losing weight, but trying to make some solid gains can be quite tough. Lifting weights for months, and making sure you get the right amount of calories can be a pain. Recently I had to take my focus off of building muscle, and go back to just losing weight. Sense I was dirty bulking I was putting on more fat.
Luckily for me I manage to burn it off within a few weeks, and now I'm probably going to bulk once I reach 180 or 190. At that point I'll probably start counting my macros. Though I have noticeable muscle in my arms and shoulders. I'll probably look ripped out of my mind once I get to 180 or 190. Though my major concern is having excess skin, and going through surgery.