I used ISDL, a related technology based on ISDN operating at the same bandwidth, for a few years in Colorado in the early 2000's. It was the only thing better than dialup at the time. The ISP was Megapath Networks. Still have the Efficient 5871 IDSL modem somewhere.

Always on, static IP address. It was easily the most reliable service I have ever used, then or since. The latency was astonishingly low as well. But 128Kbps wasn't adequate and I moved on when I could.