Focus Hosted PBX comparison guide
M5 stacks up well against Covad, Smoothstone, etc, in this cost/feature comparison guide from Focus.
The bullet point we are most proud of is support/customer service. While the other providers say yes printed, online and call-in service is included, only M5 can say sure maintenance, support, changes and upgrades are included. And 95% of support requests are resolved within 24 hours. And 95% of customers would confidently refer M5 to other businesses.
For us that's really what matters.