Pros
Adaptive is full of talented developers, product owners and project managers, many with deep technical and domain expertise. If you are looking for somewhere to learn the technical side of trading systems, or you're already an expert and want to work on interesting projects, this is the place to be.
On the administrative side, everyone there is open, approachable and professional. The team have a lot of fun with regular social events and activities.
I would particularly recommend the firm for a first job in finance / software. You'll be learning from the best in a very supportive environment and the sky's the limit!
Cons
The normal caveats about consulting apply and ultimately client demands can be frustrating. But the firm is well positioned to maintain a pipeline of interesting, rewarding projects.