Pros
The constant change in technologies means that a Consultant can never be still. There's a need to be not one, but two-steps ahead of the customer's best guess and usually one of their employees who's using the opportunity to advance their career too. The Consultancy division has improved drastically since I moved into it in 2002. We have radically overhauled and improved the internal processes and standards to a point where I'm proud of where and what we start from. I've seen design documents from competitors that have made me chuckle at their failings, and CC's are close to the quality that I see from the primary players/vendors. Travel is expected and if you like being away from home, then you get to see a lot of Holiday Inns. Oh wait... wrong category. Breakfast, lunch and dinner can be claimed over a certain milage from your home. If you want to progress your career and go about it the right way (the CC way) then the management that I've found in the past 4 years will move heaven and earth to help you plan and execute the strategy. With strong leadership, CC has weathered the worst downturn in it's history and expanded to France, Germany, BeneLux, South Africa, Malaysia, Hungary and other territories and become a major global player. Consider that 12 years ago we were shifting tin in boxes out of warehouses scattered around North London, I see that as a major Pro. and have faith in the current Exec.
Cons
The work/life balance for Consultancy is pretty rotten. You're EXPECTED to do the travel, and the administration of timesheets, expenses and milage, pretty much on your own time, but that will change soon, we're told. We explicitly asked for the work/life balance to be reviewed and basically nothing changed. Oh, except that they implemented an external service where you could discuss your personal issues in confidence with a consultant. The travel policy is pretty restrictive and you'll see a lot of their "approved list" of hotels. In 2014 they are still handing out Nokia brickphones without a data plan despite a year ago giving indications that it would change. Embarrassing.