Seems like you got the recipe figure out. Just wanted to add my two
cents.

Baking temp has a lot to do with browning and fast rise. Raising the
temp to 400 is a good idea for home bakers making muffins.

I suspect he is using a professional oven that is MUCH hotter than
what we use at home. 350 in a professional convection oven is
probably close to 400 for home appliances.

Also to note, different flour brands will definitely change the final
product. I only bake with King Arthur, unbleached white flour. I
love it!

Julie
http://www.bakingbits.com