Joe, my building is using Comcast business class internet, in a residential area in the Hyde Park area of Chicago.
I recently signed up with a reseller that uses the SIP7 datacenter. My Obi110 box has no problem connecting. Our soft-phone setup has been working well also.
My parent uses VOIPo's service out in California for almost 4 years. I tested their BYOD setup here at our building, and the SIP-datacenter in Dallas came through clear as well.

Tim, I am glad you guys are spreading out to other data centers. I read something recently that Softlayer/IBM is expanding their data centers like crazy. Softlayer and IBM knows how to run their business.
It's good that VOIPo add some diversity for customers, as not everyone enjoy the same Internet setup/experience as others. If it's not too expensive to add, consider adding one in Toronto or somewhere near for your Canadian clients.

A quick question:
Can a client (whether with VOIPo or through one of the VOIPo's reseller) choose which SIP server works for them, simply by changing sip.voipwelcome.com --> sip7.voipwelcome.com (and vice versa)?