VOIP QOS Cisco 2800 and 1800s - Metro-Ethernet

We have recently added some new Avaya phone systems to our network and are utilizing VOIP to connect our remote sites to our main site.  I have worked with the phone vendor in configuring the QOS in the routers to support this, but I am not sure I like the way it is configured.

We have 9 remote sites connecting to our main site via Metro Ethernet.  Each site has varying CIR from the carrier.  Only 3 of our remote sites have VOIP phones currently, and in the future we will be adding additional sites.

We have 1 policy-map that is applied to the physical interface where all the metro-E subinterfaces are.

I found a link on Cisco that discussed creating a hierarchical policy :
http://www.cisco.com/en/US/tech/tk543/tk545/technologies_tech_note09186a0080114326.shtml

It showed the following example which looks like it might be a better and more flexible way to do this :

policy-map child
class voice
             priority 512

policy-map parent
class class-default
shape average 2000000
              service-policy child

interface ethernet0/0.1
service-policy parent

I like this because I can create a policy-map for each site, and apply them directly to the subinterfaces, rather than the entire physical interface.

Any opinions on this?  Would the hierarchical policy method do what I want? (shape the link to carriers CIR and prioritize voice traffic up to 512kbps)

The code below is an example of what we are currently using.  It is modified from the actual config to be posted here.

class-map match-any Site-B
 match access-group 100
class-map match-any Site-C
 match access-group 101
class-map match-any Site-D
 match access-group 102
class-map match-any VOICE
 match ip dscp ef
 
policy-map VOIP
 class VOICE
  priority 512
 class Site-B
  shape average 2850000 28500
 class Site-C
  shape average 1900000 19000
 class Site-D
  shape average 1900000 19000
  class class-default
  fair-queue
  random-detect dscp-based
 
interface GigabitEthernet0/0
 description To Metro-E
 no ip address
service-policy output VOIP
!
interface GigabitEthernet0/0.1
 description WAN interface to Site-B
  ip address 10.1.1.x 255.255.255.252
 !
interface GigabitEthernet0/0.2
 description WAN interface to Site-C
  ip address 10.1.1.x 255.255.255.252
 !
interface GigabitEthernet0/0.3
 description WAN interface to Site-D
  ip address 10.1.1.x 255.255.255.252

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NetworkDiagram1.jpg