I have been a long time user of the Nik plug-ins, and a more recent user of the OnOne plug-ins, which I bought as a Suite, when they were offered at a sizable discount over buying the individual plug-ins. I find that Nik is more useful for general photo editing, i.e, getting my photos to look great, and I have an established workflow for accomplishing that task. OTOH, OnOne is more useful for specialized functions, such as resizing, retouching portraits and selective blurring. It has some cool Photo Effects as well, but most are of little interest to me. So, for me, it is not an either/or question, but rather one of choosing the right tool for a given task. I suggest downloading trial versions of both as the best way to learn what works for you.