It is a solid company. Many just talk about the Big 3, those being Sunlife, Manulife, and Great-West, but IAG has definitely carved out its own space.
The Big 3 are primarily yield plays. Mid to high yielders that although have done well as of late, do not typically provide large scale share price returns. IAG is more of a growth-tilted insurance play. Instead of returning a lot of their capital back to shareholders, they spend a lot on acquisitions. For example, they're entering and expanding aggressively in the US via some key acquisitions.
This is all great, but the company needs to execute. If it does, I'd expect it to continue to dominant the Big 3 in terms of total returns.
My only difficulty here is that I do believe it is priced to perfection. It may seem weird to say this at a 15.5x P/E, but these insurers simply do not trade for this high of valuations, typically. In fact, IAG has usually only traded for around 12x earnings.