Pros
I've worked agency-side for a long time and Wolfenden is one of the better agencies I've experienced. The people are smart, down to earth and easy to work with. There isn't a lot of politics and I've always felt trusted to make decisions and get on with my job. The client work is varied and expectations are high, which won't suit everyone, but if you're someone who likes being challenged it's a good place to be. Senior leadership are involved, know the clients and care about the quality of work being delivered. I've also found the agency to be fair. When people do a good job it's recognised, and when there are problems they're generally dealt with directly rather than being allowed to drag on.
Cons
The pace can be full on at times and there are periods where everyone is stretched. That's probably true of most agencies though. As the business has grown, some processes haven't always kept pace, but that seems to be improving.