Integrated T1 vs. PRI / Full Data T1

We currently have an integrated T1 with 12 Voice channel (8 trunks, 4 DID) and 768K data. We've had this T1 for 3+ years and have outgrown the data side. We're looking for full T1 speeds for the next year and probably more down the road. We're doing a good amount of cross country VPN. As we're not exactly thrilled with our current provider's service (XO communications) or its 2001 pricing. We've been looking into a few other providers. I've got quotes from Broadwing (focal?) and Telepacific and of course SBC. It seems that they're all pushing a PRI and Full T1. While a PRI looks nice, we don't really need 23 lines and we'd have to buy a PRI card for our Altigen PBX for around $3000. On the other hand, Broadwing is offering an Integrated T1 with "dynamic bandwidth allocation". Apparently, this means that through ATM, unused voice lines will switch over to data and revert as needed to voice, giving us a much higher average bandwdith than the 768K.

Here's the question: Does anyone have any experience with:

1. These companies (Broadwing/Focal and Telepacifc)
2. Dyamnic bandwidth allocation in an intgrated t1
3. What's a normal SLA to expect for this kind of service?

I'm also a little worried about broadwing's financial situation. Points for any good info on that as well (already went to yahoo finance).