[CentOS] Can anyone talk infrastructure with me?

Hi John, 
> > Are you using Comcast in Santa Cruz?
> 
> absolutely not.the local cable system blows. my home is on a sonic.net (http://sonic.net) 
> ADSL circuit resold by another ISP. television is on satellite.

I am looking at Sonic.net and I am awaiting a call from a sales rep (had been 2 days) 

They are offering a "Business T" for $308 per month and I also see they have the bonded 

They advertise the starting "Business T" at 1.5Mbps per second 

They advertise the ADSL2+ 2 lines at up to 40Mbps per second.

Am I mis-understanding that the cost for a T seems high, but a better option for me than getting their ADSL2+ service? I mean, is the "T" faster over all given it is all my traffic and I am not sharing?

Can you explain a bit so I can develop a better understanding of how they advertise speeds, etc?

-Jason