illuxion:
For simple 3.3v to 5v shifting an N-FET level shifter works fine at the speeds we're doing.
Maybe, maybe not.
illuxion:
The slew isn't the peppiest around, but it the same thing adafruit calls a level shifter.
Adafruit does in fact, not recommend it for this purpose.
illuxion:
4 N-FETs and a few pull down resistors gives you 2 channel bi-directional level shifting and it wiggles fast enough to drive a WS281x.
Bidirectional is meaningless in this case.
This might have worked for you, so far, in your particular application, but we cannot ethically afford to offer advice that will fail in a proportion of cases. 