I go all-out retro with candles… 
The only time I got LED lights was to scrounge them for the LEDs themselves (60 or whatever for 8bux on sale).
On a tree, they have an annoying 120Hz flicker at maybe a 20%-or-less duty-cycle. You thought taillights and daytime lights on cars were annoying? Try seeing a dotted Christmas tree in your peripheral vision every time you move your eyes.
Technically, being that they’re 2 separate strings wired in anti-parallel, each string pulses alternately at 60Hz at a teenytiny duty-cycle, only near the peak of each AC cycle. They’re like 2 sets of mini-strobes.
Stick with hotwire bulbs. You’ll thank me later.