I am the owner of a Call Centre automation company in New Zealand, also servicing the Australian market, specializing in Outbound operations. I have sold a number of different predictive dialer systems over the last 10 years.
I'm writing to give a big tick to OPC Marketing - I have placed their systems into sites ranging from just 4 agents up to 70. Each site has different connectivity methods, via a PBX via E1 or T1 cards, via analogue flyleads, plugged directly into Primary Rates, SIP to PBX, SIP direct to SIP trunk provider, even out to GSM-Gateways with flat monthly call plans.
The huge change from the previous systems I was selling, was the on-site tweakability of the system to suit whatever the local environment was; config screens and ini files make for a very flexible toolset and easy installs.
Oh, and I noticed a review talking about voice quality and SIP - well, actually it's all about the bandwidth buddy. I've got numerous Spitfire SIP sites up and running (4 agents, 12 agents, up to the biggest SIP'er with 32 agents/64 SIP lines) with excellent voice quality, but 1/ only on sites with sufficient bandwidth guaranteed on their internet connection to handle it and 2/ using the G.729 codec whenever I connect directly to the SIP trunk provider.If you take care of the bandwidth, the system itself is sweet :-)