Recently MTNL mumbai announced special speed upgrades at night.
I am currently on 999 unlimited plan since 3 years now and MTNL has kept me happy. With every new year, there has been a speed upgrade. This time its not a speed upgrade really, but you will be getting higher speeds at night and on sundays if you are on unlimited plans.
I am getting ~1.5Mbps down and 700kbps upload bandwidth after 10pm at night.
The problem with this upgrade is that, it is completely automatic, and exactly at 10pm the internet disconnects for exactly 5 minutes and reconnects back. Its annoying if you are on a VoIP call or if you are between a multiplayer game match.
I hope MTNL takes notice of this and does something about it.
Another tweak I found recently that, if you change the modulation type to G.Lite in your router settings, you are able to get amazingly low pings to any IP in the world.
Default modulation is ADSL2+. With this default, I was having 90ms ping to the mtnl server itself! Later, I found out, with G.Lite was able to get 5ms ping to mtnl servers. I am able to play games with low latency.
Also, MTNL has recently publicly launched its new beta site http://beta.mtnlmumbai.in
You should check it out. Definitely worth checking out.