Pros
As an independent and mid-sized agency, you are not just a small cog in a big machine. Everyone has a voice and you can be master of your own destiny, working across a really impressive and varied client base with the freedom to try new things.
Not as 'product based' like a lot of agencies, so you get to use your brain and come up with new and interesting research approaches. A great place to learn your craft with lots of opportunities to work on a variety of sectors and research approaches - which you don't get at bigger agencies, and working with clients you wouldn't find at smaller ones.
Everything is team based and it's a flexible company to work for - senior leadership is clearly working hard to find new ways to recognise and reward people's effort. Better work-life balance than at other agencies.
Cons
Being a mid-size agency, commissions are important so there is a strong commercial focus - but this is important to any business. Does mean that sometimes you can't benefit from the 'progression treadmill' seen at other agencies (e.g. promotion because of time on grade, rather than based on a business case), but it is a meritocracy and hard work is recognised.