[TristanBall]

It first glance this seams really cool, but I have to wonder how much the use of timestamps increases the chances of duplicates.

[arp242]

It still has 62 bits of randomness; you have 4,611,686,018,427,387,904 values every millisecond.

I would judge the chances similar to UUIDv4: theoretically possible, but the chance is so small it's practically impossible.