I am a VERY happy customer of DataOne since July 2005. Heres my experiences of DataOne (Pune Telecom Circle)
Getting it
I asked for Dataone service, and the telephone check report was done in about 2-3 days - there was a line fault (due to too many parallel connections), which got sorted out in another 2-3 days.
The modem took a while (4 days) to come, but overall the service was installed in about 2 weeks time
I got my username and password the same day the modem was installed, so I could get online asap
Service Quality
Overall, since the last 2 months, there have been only 2 service hiccups -- once when their authentication system was unreachable (about an hour) and once when their DNS was overloaded / not working (about half a day). Internet access speeds are as advertised (I actually get 40k - 45k byte / sec download on their 384kbps Plan-1000)
Resolution of issues
Their toll-free customer service number is NOT for technical problems, and the local number for tech support is always busy. BUT, if you go to the exchange, any problem gets sorted out pretty fast. Hopefully they will have a technical helpdesk soon.
Problems
The biggest problem is that they have data transfer caps (1 GB for Home-500, 2 GB for Home-1000, 5GB for Home-1800). So if I want more data traffic (or even unlimited) -- its not an option. This is my biggest gripe with Dataone
Besides these, so far, Ive had only a minor set of issues:
Online interface of DataOne (where you can check your service records, etc -- https://dataone.in) works with IE only. I told them as much yesterday, hopefully itll be fixed soon.
I dont get a monthly total bandwidth used anywhere. They are still working on it -- hopefully if enough people complain, that will be resolved fast too.