I have about the same advice from my cardio -- "If it feels good, do it. If not, don't." Of course, he smirks at me when he says this, knowing that I am still taking 25 mg/day of metoprolol, and no matter how hard I try, I can't get my peak heart rate above about 145 BPM. Until my early 60's, I was running/jogging daily, often maintaining a max heart rate of over 160 BPM. I had no issues with rate then. After surgery, I had a tendency toward tachycardia and afib, hence the beta blocker. I also have a pacemaker, but it has no impact on max heart rate, as I rely on it only for ventricular pacing. My atrial pacing is all natural about 95% of the time.
It is probably a good thing that my cardio and my electrophysiologist both told me not to worry about the actual number of my max heart rate, because I have yet to find a monitor that will dependably read my rate.