One loss is the ability to use LiquidSoap as a source for hold music in Asterisk (even though the capbility can be recovered, it doesn't yet "fit well" with Icecast or Asterisk inputs).
At first, I attempted to use 64-bit Linux, with the objective of using LiquidSoap for a number of features. I had so much difficulty in getting Liq to work that I abandoned the 64-bit effort. Little did I know that it wouldn't work in 32-bit either.
To make a long story short, time constraints have left me with a 32-bit box with a borked Liq (only plays OGGs) and a number of work-arounds to get a few functions (Asterisk, MythTV, etc.) working. I've even resorted to using SqueezeCenter as a hold music source in Asterisk. It's overkill, using way too many processing cycles to provide a single function, but it works.