I get a lot of funny looks when people would see that he was still facing backwards, and while I won't go into details here, I will say that we decided to stick to our 2 year rule (as we did with Jake) based on our own research and what we felt comfortable doing. If you have concerns about rear-facing that long (like whether or not his legs would be injured in a crash, if he's comfortable, etc...), there are many you tube videos out there that answer those questions, and show the difference in crash tests of rear-facing vs. forward-facing.
From our own personal experience, I can say that neither of the boys were uncomfortable or complained about the carseat being backwards. They both have long legs (Liam especially), but he would just bend his knees and let his legs fall to the sides once his legs got too long to stretch out all of the way. Sometimes he'd even sling one leg over the side of the carseat, in super-relaxed mode!!