I have used Hathway, Spectranet, Airtel and ACT broadband service in Bangalore. And ACT fares the best among them all. Below are the places where it shines:-
1 - The speed is consistent and as promised. After using it for more than 2 years I have never seen speed less than 20 Mbps, which was my plan.
2 - They do not count your uploads, so I always seed my torrents 24/7. Both Airtel and Hathway used to count upload speed and that makes your FUP drain really fast.
3 - Prices are very reasonable.
4 - Very few down time from their server.
5 - On call customer service is prompt and available.
If does have some major cons though:-
1 - There may not be a lot of disconnection; if they do occur, however, it might take a while to get it back. Once it took 3 days and then for another it took 1 day. Most of them are due to electrical issues with the connection box they set up in the building.
2 - It is available at only few places.
3 - If you shift to a new location, even if there were open ports, it would take 10-15 days to get your current connection transferred. It is better to get a new connection instead.
4 - You pay at the beginning of every month so if you were to disconnect in mid-month, the rest of the money stays with them.
5 - They you multiple network switches internally. So you can’t set up DDNS on you router. DDNS is helpful for accessing your router web page even when you are not in home.
But even with these issues it fares better than Airtel(who charges exorbitantly and also a fraud - charged us 12GB in 4 hours for a 4Mbps connection - impossible) or Hathway(frequent disconnections and beyond pathetic on call services - I used them last in 2007 though) or Spectranet(this was also fabulous except it had no online payment option - an issue for me).