Topher is almost a year and a half old now, and we decided to try and let him use a pillow now. He always hits his head up against the crib bars, so we've been using his stuffed tiger as a buffer until now. But he loves pillows and always lays on them correctly when we give him one, so we thought we'd just put one in the crib and see what he does with it.
He's been sleeping wonderfully ever since. It's probably not just the pillow. It's probably a combination of having his fan on, dressing him cooler (since the weather is warming up), and changing out his bedding to cooler summer sheets, but he's been sleeping like a champion and we are SO appreciative of every good night and every good nap he has. It makes everything else so manageable during the day if we're all well-rested. And we realize this could just be another lucky sleeping phase, so we're soaking it up while we can.
The bonus of giving him a big-boy pillow is that he loves it so much, and no one could look more adorable on it than he can. A baby discussion group online confirms that many other kids his age sleep much better with a pillow. If Topher keeps sleeping this well, I'm going to kick myself for not trying this ages ago! But this is how we mommy-dummies figure things out: the hard way.
I'm just glad the hard way here was as simple as a soft pillow.