I've owned the Silverface and Blackface versions. Their sounds slightly differ: the Silver favors high mids, while the black is richer in the low mids, but it's really, really subtle!
What's nice with such pieces of gear is how simple they are: you only tweak the ratio, threshold and output level and it always sounds right.
The problem with them is... how simple they are! Either it gives you straight away what you expect, or it no use insisting and you'd better gat after something else.
Its sound remains quite neutral colorwise, the release setting is rather slow. Compared with other gear I have I mostly use it for a transparent sound treatment and "technical" compression so as to only keep the signal without a real impact on the sound itself. I's been my first "serious" compressor and I like it, it's a nice little unit.