I drink coffee for the taste, not really for any boost.
A good decaf is calling you.
*makes coffee to read thread*
Although 4pm is probably the latest I'd have a coffee these days
Yep! By 9pm you'll still have 50% of that caffeine circulating your blood, and still 25% during the early hours. You may be able to fall asleep easily (I used to) but you'll be missing that deep sleep. This was key for me as someone who exercises a lot, that's where the recovery happens.