Yeah, there is a whole subjective component to all of this that is hard to get good information on. I am older, and drink both tea and coffee depending on mood

Yeah, there is a whole subjective component to all of this that is hard to get good information on. I am older, and drink both tea and coffee depending on mood, need for caffeine, etc. There are some online guides that give ratios of caffeine in typical tea versus typical coffee. Of course, figuring out what "typical" is is the issue! What I've seen shows that black tea has quite a bit less caffeine per serving (bag, infuser full, etc): 1/10 to 1/5 of coffee caffeine. However, there seems to be a big difference in coffee strength! As an anecdote, I personally find little difference in caffeine between weak coffee (Dunkin Donuts regular is a good example) and a strong black tea (Tazo Awake, for example). On the other hand, Starbucks drip coffee is like getting a meth injection! Immediate symptoms: increased heartbeat, "speedy" feeling, fidgeting, etc. Also, I hear you on water temps. At home I use an aeropress and 195 degree(F) water for coffee pressing. To me, there really is a taste difference (less bitterness, mainly) if I leave the water just below boiling, but some people don't see any difference and like their water hotter. Experimentation seems to be the only way to get to your caffeine happy place!