NY Biker said exactly what I feel. For me, heart rate data is irrelevant. And while it would be interesting to have a lactate threshold test, and all that, I'm not racing. RPE (perceived exertion) is fine for me, especially since I *know* and can almost predict to the number what my HR is and what zone I am in. If you are new, the data might be useful, to learn how your body works. Intervals are the key to any training plan and hills, lots of them.
The mood thing is key. I often want to go on a hard ride and then get in a bad mood when I am doing it. Usually, it's because I feel like I am not keeping up with the goals I have set for myself, others are riding better than me (if I'm with others) and I get pissed! The stars all have to align for me. I am pretty good at suffering, but if my mood is off a lot, I scale back and do a lot of short rides, or "errand" rides. You need to find out which combination of ride types works for you, as well as log your mood. Of course, once I am done, I feel great and I forget about the suffering!