Riverbed likes to pride themselves as being ahead of the pack, family oriented and in general... smart. Instead, they have a tendency to focus on buzzwords and trivia, and rely on a large and overly dedicated workforce to constantly pick up and run with the various balls that management drops when it comes to actual engineering. Wonderful products, but the process that leads to those products is haphazard and detrimental to working a 40 hour work-week.
Riverbed makes a big show of hosting an internal employee training group. If you are a peon, the only courses available to you is how to make better use of Microsoft Outlook's scheduler and like ilk. Do not expect to get support for taking outside classes, or having any kind of help on gaining any training or continuing education that would be of actual benefit to your field of work. If you are management however, you get some amount of training on how to be a better manager - by learning how to pigeon-hole the 'types' of workers you have under you, how best to fire those who use up too much comp and vacation time without getting in trouble with the law and how to excuse constantly giving 'adequate' performance reviews no matter the quality of an employee's work.
Management is primarily an old-boys network. If you're a long-timer at the company, expect to start seeing junior folks hired at higher than your salary. You will never get an excellent review (see above) and the way raises are calculated, you'll never see better than a 2-3% cost of living increase. If you get more, someone else in your peer group is being shorted. Though they make a big show of broadcasting when promotions happen internally, the bulk of new management comes from outside the company and promotion internally is fairly limited. Some groups have created new titles to give people the feeling of a promotion - without actually having to give one.
The company spends a lot of time internally trying to get employees to advertise for the company by taking these 'best company' surveys, signing up employees for similar surveys, and constantly having internal promotions to make employees sign up for various social media outlets to 'broadcast' marketing's message. Heaven forbid if you go off-message or don't sign up. You likely will be pestered.
Expect to work in an open-plan, noisy and distracting environment. The CEO read one report that this environment leads to improved collaboration (and has a much, much lower cost per person) and has mandated that all offices must have the exact same open-plan furniture, color scheme and layout. Depending on how much of a stickler your local management is, you may not be allowed to hang anything around or on your desk. This is all excused by 'management is in the same arrangement.' Sure, except that upper management also usually have a group of desks to themselves, away from the rest of the work-force - when you can even find them at the office.
There is no flex time, there is no work from home during office hours. There is plenty of work from home during non-office hours. Some managers allow some sliding of these rules, but there's another push coming down to try and get everyone back 'in line.' You will be labelled a non-team player if you dare take vacation anywhere near a project deadline. There is always a project deadline. It is fully expected that people on vacation have their cell phones and laptops with them. It isn't required, but it is expected. You know how it goes.
In the end, Riverbed isn't a horrid place to work - it is just like the rest of corporate America. It just spends a lot of energy trying to pretend that it is different. The above (and a lot more left unsaid) is simply to let you know that if you want to work here - you'll find it the same as working for any other large company. No better, no worse.