It's not a terrible process if you know what to expect, but do be prepared to spend a lot of time filling out paperwork.
I applied online through my university's career center. A week later I get an email asking me to take an online assessment, which I do. Same IQ, personality, math sections that everyone else had. A few days afterwards, I get a follow-up phone call from a HR recruiter who wanted to clarify some questions about my resume. She was very nice and polite through the process, and it ended with me moving on to a Skype call with her in two weeks. During the Skype session, she was again very polite and outgoing; she asked me to fill out an Ethics Assessment, an extended application, and a background check permission form at the end. I did so; a day later I got the dreaded "we will contact you in 3-5 days", and 5 days later I was told the application process was not moving forward.
From my own experience and from others' comments, my advice to potential applicants is to anticipate each step in the process and be ready to respond to what is expected of you. This company is very stringent about adhering to its process, so you need to read all of their instructions carefully. The ethics assessment clearly stated that you should try to answer "totally agree" or "totally disagree" as much as possible; I did not do that and I believe that contributed to my rejection. They will not hesitate to drop you at any point in the process if things are not going the way they want them; this will be prefaced by a vague and formal message about "contacting you in x number of days." As soon as you get this, you should really start to cut your losses; at least reducing it so you don't have everything committed to working with the company.
Bottom line is this: if you really want to work for this company, read up about its history and policies and listen carefully to everything the recruiter tells you. Follow ALL instructions to the letter and be proactive in asking questions if something is unclear. If you start getting really formal and vague replies, cut your losses and move on to another application. They know what they're looking for, and if you don't fit the bill then you're chances are slim.