Pros
The people at Signiant are excellent. Everyone is extremely competent and good at what they do. The company recently switched to Agile, which further improved work environment and helped with workload management. The company has a well engineered and mature family of products and is also not afraid to start new and exciting projects. The salaries for strong contributors are quite competitive.
Cons
There are no deal-breaker downsides to working at Signiant. Their location - Kanata instead of Ottawa downtown could be considered a downside by some. The building they are in doesn't have any shower facilities, which doesn't encourage biking to work or working out at lunch time. Their office space itself is a bit shabby, but they are in the process of improving it. Even though the health benefits are there, they have been getting worse as of recent. Moreover, there are no RSP employer contributions or bonuses for developers, which would be a huge nice-to-have. Having said all that, none of these issues are deal-breakers and the pluses of working with extremely motivated and cool people on interesting projects and earning a very good salary mostly outweigh the few minuses I can think of.