Yes, well actually I noticed that I sleep well directly after drinking coffee, but I thought it's because of the warm drink in my stomach (like a hot chocolate for kids).
I also discovered that drinking a lot of coffee all day isn't helpful for sleeping :-)
If warm drinks make you nap better this is even a bonus :)
Yeah to much working caffeine is not good if you want to got to bed!
But drinking too little caffeine isn't good either, if you're an addict :-D It's hard to find the balance...