The concern I mention is that the brightness "limitation" is by means of PWM so that each individual LED at some part of the time may draw the full current - 60 mA per LED.
This depends of course on whether you are expecting a single primary colour or a mixture, and whether you are lighting just a few LEDs relatively brightly or many just dimly. In the latter case, if the PWM cycles happen to synchronise - and I do not know to what extent this will happen in a strip of WS2812 - you may still get very substantial impulse current draw.
It follows that if you are generating patterns where just a few of the LEDs are illuminated at any one moment, and with a primary colour, then you may mange with a 5 A supply. These strips as such, lend themselves to "chasing" patterns.
I would still advise placing the 470 µF or 1 mF capacitors every 60 LEDs and at each end to suppress these impulses, and you should ensure that 5 v, ground and data wires where relevant, travel as a pair or triplet, generally using "figure 8" or ribbon form cables and connect together to the strip at the same place. The requirement is to avoid open loops between supply and ground or data and ground.