I was recruited for the position, phone screened, brought in for an interview with people I would be working with, brought in for assessments, and brought in for a final interview with recruiters. I expected to meet with some directors or senior-levels for the final interview, but was basically asked the same questions I had already answered in the phone screen. The process was by far the most thorough I have ever been through personally, almost like applying to college.
Like others have said, their reliance on tests do prevent certain candidates from moving forward. I expected more questions related to the actual job itself, but it was more pattern recognition, anagrams, and "name a time when you solved a problem" type stuff. The process was a little canned and awkward for someone not fresh out of college.
It's clear ROI Revolution goes above and beyond to hire smart people, which is great if you're not used to working around a bunch of them. I just don't really think assessments (or GPA prerequisites) can really measure intangibles like empathy or the ability to interact with others. Some Bay Area companies (like Google) just don't prioritize these qualities over book smarts, so everyone tends to fit the same profile and the workplace isn't as diverse as you may think.
The recruiters were nice, and it was a good experience overall. Keep in mind that this process is pretty time consuming, as there are multiple phases you have to go through.