I roasted my 3 - 4 lb bird for 50 min at 350.
The meat was perfect and it was easier to carve into segments. The skin looks crispy but it was actually pretty floppy. My tried-and-true roast chicken recipe from Joy of Cooking has you preheat the oven to 450 and then drop it to 350 when you put in the chicken- and then roast for 20 min per lb. That's 1 hour and 20 min for a 4lb bird. The spatchcock method is faster but the skin wasn't as good.
So, I'll try this again but I think I'll preheat to 450 first, then drop it to 350 when I put in the chicken. Or roast the entire bird for a shorter amount of time at a higher temp. Perhaps 40 min at 400? That would be a treat to have a whole chicken done in 40 min after becoming accustomed to it taking nearly an hour and a half. But the skin's gotta be right. It's gotta be right. It's like making a pie and the crust being wrong. It ruins the whole thing.