I do think they have a good system, but their inventory of sites is much smaller and updated less often. I have a few good links that don’t show up on there at all.
From some research it also seems that it doesn’t have too much impact on rankings. I have seen similar sites, one that had high page & domain authority on OSE and the other which outranked it for every term. Unless the first guy had horrible on page it would seem OSE wasn’t a really good measure of what it took to rank, which quite frankly is all I am concerned with.