Pros
Trident is a very close-knit group. The open-door policy is awesome; you can approach and talk to just about everyone in the company, all the way up to senior management. The benefits are hard to beat and the great people make working here very enjoyable. The office environment is laid-back, with flexible hours and generous PTO. Everybody is very good at what they do, with only a few people that seem behind the curve. The senior engineers and scientists are world-class, yet very reasonable and easy to talk to (no inflated egos). There is little bureaucracy - few middle managers mean senior management is very close to engineering and thus the two are nicely aligned. Management is very hands-off, so each employee has a good deal of autonomy. That means you have the freedom to decide how to approach problems and how tasks should be done. That is not to say you can't get direction or help when you need it, just that you are not micro-managed or having somebody else's work style imposed on you. There is very little "fluff" work; everything has a clear purpose.
Cons
Some of the non-technical people have entrenched themselves and flat out refuse to train new employees, to the detriment of the company's current operations and future capabilities. Directors and the HR department do not seem able or willing to fix that issue. The small size of the company means there are few positions to aim for. This is mitigated by what seems to be the alternative "lateral" movement - engineers will be promoted into a senior position created specifically for them to move into. While that works out in the long-run, it is tough to set your sights on something that doesn't exist. The project management could be much improved - there seems to be little coordination amongst the project managers in general.