IPv6 prefix lengths

Hi all, What IPv6 prefix lengths are people accepting in BGP from peers/customers? My employer just got a /48 allocation from ARIN, and we're trying to figure out how to support multiple end sites out of this (probably around 10). I was thinking about assigning a /56 per site, but looking at the BGP table stats on potaroo.net [1], it looks like this is not too common (only .29% of prefixes). Thoughts? Thanks, --Richard [1] <http://bgp.potaroo.net/v6/as2.0/index.html>