It really depends on your carrier. Over here in the tri-state area, Verizon's the carrier, and they recently screwed me over. I ordered service through Winfire, and because I didn't want the modems Winfire ordered, I went ahead and bought a modem compatible with the Verizon service myself. Shortly after, I received an email from them that they did not have service in my area (even though they informed me that there was service in my area a month before) and canceled my activation. So now I'm stuck with a modem but no service.
Winfire's tech support is pretty crappy too. They don't know much, takes forever to get someone on the phhone and forget about email. However, i don't think you'll have to worry about them going out of business. They have other plans such as the $10, $20, and $35 plan...
Lastly, check out
DSL Reports