I have been using spectranet since last month or so after repeated issues with airtel. While I would like to state that customer service depends purely on helpfulness of the technician in your location, it would be the same case for any broadband provider. If you have a helpful technician it is best to take his personal number and contact him for any issues directly.
Now coming to the connection, it has been reliable and fast connection. While speed isn't as consistent as ACT, the 20 Mbps connection which I have provides more than sufficient speeds(minimum 15 Mbps) throughout the day and promised speeds during the night. We are 3 people who share the connection and hence use 3 laptops, mobiles and a PS4.
For me personally a connection with no FUP was mandatory since I have a PS4 which consumes large amount of data. They also have a 50 MBPS plan which I have heard is very good from my neighbours as well. All in all am very satisfied with the connection as all 3 of us love to download movies and stream videos online that utilise large amounts of data and require good speeds. The prices are very reasonable but only catch is that you need to pay on a quarterly prepaid basis. Personally very happy to have moved from FUP restricted airtel to spectranet.