If you're noticing a difference with NO2 and you like it, I won't suggest that you quit it.
If you've been doing that same workout for a while, or something very similar to it (3 sets, high reps, etc.), I'd recommend changing it up. Work on increasing strength for a while. I also notice a lack of overhead pressing. It's been said that the military press is the squat of the upper body. Those are words to live by, IMO. I also don't see any deadlifting, which should be a staple in any lifting program.
Here's a good routine that combines the low-rep strength work with higher-rep hypertrophy work.
M Upper Body (horizontal plane)
5x5 Bench Press
5x5 Bent Over Row
5x5 Skull Crusher
5x5 EZ Bar Curl
T Lower Body
4x8 Squat
4x8 Standing Calf Raise
4x8 Cable Crunches or Swiss Ball Crunches
W off (cardio/GPP is ok to do on this day if you like)
TH Upper Body (vertical plane)
4x8 Military Press
4x8 Pull-ups (weighted if you can)
4x8 Weighted Dips
4x8 Hammer Curl
F Lower Body
5x5 Deadlift
5x5 Seated Calf Raises
5x5 Decline Bench Sit-up
Sat off (cardio/GPP is ok)
Sun off completely
Don't go to failure unless it's the last rep of the last set. Leave about 2 reps "in the bag" for each set. The point with this program is to build up your strength, so failure training is not conducive to that goal. If you want to do "forearms," work that in wherever you want, but I'd recommend replacing that with grip work such as Captains of Crush grippers, plate pinches, farmer's walks, etc. Remember, this is a strength "mesocycle." Build up your strength, and then if you decide to go back to your standard bodybuilding-style routine, you'll have a better strength base to work with, and thus, more muscle stimulation.
After about 4 weeks of this program, switch the set/rep schemes. So Monday would be the same lifts, but with 4x8 instead of 5x5. Etc. I think you'll be surprised at how much stronger you are after 8 weeks. Of course, if you like it, you can do another strength program after that and still build some serious muscle. Don't fall prey to the myth that you have to do high reps to build muscle. Low reps and high sets will build muscle too, and maybe even better than high reps. But do what you like doing because results can be had either way. That said, it's also important not to totally neglect either of them. If you like high reps, your training should also have periods of low rep strength training. The key is to change it up.
For your cardio and GPP, do whatever you like doing. There's a pretty strong argument that sprints, HIIT and the like are superior for burning fat while maintaining muscle, but the truth is, if you don't like doing it, then why bother. I personally don't like distance running, so I do the higher-intensity stuff, but just stick with what you like.
Keep in mind that the most important aspect of meeting your body composition goals is diet. Keep a food log, it only takes a couple extra minutes per day and after a while it becomes second nature and you won't have to look up nutritional info much because you'll know it. Make sure you're getting 1-2g of protein per pound of bodyweight whether your bulking or cutting. Eat healthy fats and supplement your diet with fish oil. It's not expensive and the health benefits are numerous. Eat lots of fruits and veggies, especially spinach, broccoli, salads, etc.
Did I miss anything?
