Maybe it's just my imagination, but this does seem to take longer than it before.  Last year, I could buy some bitcoin from Coinbase and transfer it to my Mycelium bitcoin wallet and it usually took just a few minutes.  A couple weeks ago, I bought some more bitcoin from Coinbase and transferred it to my Mycelium wallet and it took over 3 hours before it showed up.  I was getting worried for a while there.