I’ve been using MTNL’s Triband in Mumbai for about 3-4 years now. I started off with the minimum monthly plan – Rs.249 (500 MB usage) & have lately moved to Rs.399 (1 GB usage). I have been normally getting 1.5-1.7 mbps speeds ( speedtest.net ) against their advertised speed of 2 mbps.
I mainly use if for general browsing & mails, moderate downloads (songs, software), YouTube clips etc. The overall connectivity has been trouble-free.
For minor issues, the 1504 helpline is good enough, though like most helplines, they keep you on hold for a long time, before responding. However, if there is a major connectivity issue, that cannot be resolved through the helpline, it can take a long time to resolve.
The local linesmen, though trying to help, are limited by their ability & technical knowledge. At such times I have had to visit the exchange, meet the manager, get someone to attend to the technical problem. This can take upto a week & can be frustrating. I have experienced it 4-5 times so far.
The silver lining is that you interact with MTNL’s own staff, who can be held accountable for your issue. In case of some of the private ISPs, the service component is outsourced to some agent, who has no accountability & escalation is extremely difficult.
In terms of cost, I believe the Triband service is among the most inexpensive & yet offers good speed & connectivity for routine usage.
Of course for some critical use, it may be wise to have some back-up service in case of a long service interruption. All in all, this is a fairly good value-for-money option for home usage.