[c-nsp] Media Gateway recommendation

[Cisco NSP]

Our company is looking at acquiring an AS5400XM as a media gateway for our
voip platform.  Our particular configuration simply requires support for 4
PRIs with accompanying DSPs and SIP.  We don't have a need, at the moment,
for some of the more advanced features such as TDM switching but like it's
capacity for growth.

Is anyone using this platform in a similar environment with comments on
performance?  

Does anyone have other recommendations for a different media gateway
platform.. cisco or not?

Thanks for any feedback.