The Proof 1886 Quarter is very similar to the 1884 and 1885 Proof Quarters except there are more Deep Cameo examples known of the 1886. Also, a PCGS PR68DCAM example is known of the 1886, which sets it apart from the earlier dates, where there are none..
PCGS and NGC have certified a large majority of the original mintage of this date. As these numbers approach the mintage figure of 886, the number of new examples that enter the market will drop dramatically and the populations will solidify. This should make the best coins even more valuable because the fear of better coins entering the market will disappear.
In the meantime, collectors should seek to acquire the very best examples they can afford and avoid lower grade, hairlined examples.