The main problem with alliance is their 24 Online Client, don't know whether PPPoE connection is possible over alliance.
And how can we forget, even a glich of thunderstorm and Alliance shut it off.
I used Alliance, then moved to BSNL.
Used to face too many problems...like..
1. They provide static IP, so if someone in our locality is downloading from rapidshare or other file sharing sites, I couldn't download anything as for free user simultaneous downloading is not possible. Again there is problem of per day Quota.
2. Torrents, couldn't do port forwarding and all, and never used to get better speeds.
3. Don't know why, but I never used to get more than 8KB/s download speed at my 512kbps connection.
4. "No Server Found" error now and then, when trying to connect.
5. They shut off everything 1 hour before and after(each) power cut.
6. A single glitch of thunderstorm and Alliance is down. So please don't even try to guess what happens in monsoon.
Well, all these are my personal experience, and it's been probably 2 years that I got shifted to BSNL.
And really never face any problem. Ya little downtime but that too rare. Can't even compare with Alliance.