Vantaggi
They have lots of pretty good and interesting tech, which you will learn about. Everyone is pretty friendly, including senior management, some especially so. You will not be sidelined or ignored, you will always have something to work on and managers will take an active interest in you. You will be able to meet with the CEO, CTO, and other high level people, fairly regularly. TT is a great training ground for aspirational software engineers and financial service professionals. You get out what you put in. Also recruiters will like you. (Assuming they know who TT are.)
Svantaggi
Salary could be better. You will likely receive some bonus but it is unlikely to be huge. It would be difficult to see how one could "progress" within the relatively small company, except to say there is a lot of opportunity to develop your engineering skills.