SBC - CUBE or Acme or Sonus?

Does anyone here have any recommendations for SBC on enterprise edge SIP trunking with Verizon? Probably looking at something that can support up to 4-5k concurrent sessions. Seems to be fewer and fewer differences in offerings between the two venders. Acme and Cisco seem to be the top 2. I typically here Acme packet is more expensive?
Comments
CUCM SRND 9x/10, UCCX SRND 10x, QOS SRND, SIP Trunking Guide, anything contact center related