So far in Bangalore I've used Hathway (in two different areas), Act and Spectra.
Hathway
Uptime was pretty ok, occasional downtimes due to cable cuts etc, however the performance really sucked in both the areas where I used Hathway. Speeds were never consistent, and performance was sluggish, video streaming buffered most of the time. I would NOT go for Hathway again.
Act
Never had any major issues, the connection and installation experience was quick and good. Speeds were consistent always, quick and response always. No issues with video streaming. Uptime was pretty great too, if I remember correctly over the 7 months or so that I was on Act, there were downtimes due to cable cut about 3-4 times, and all except one was fixed the same day after registering a complaint with their App. The other was a major fibre cut somewhere due to the rain/wind and it took 24 hours to be resolved (opened ticket at around 1 PM, but was fixed only the next day around noon).
Act mostly terminates the fibre at a common location in the area and then from there runs ethernet to your house. I am guessing they'd have a 8/12 port
gigabit switch which shares a 1 Gigabit fibre link, so depending on the usage of the other customers sharing the same switch, you may experience issues. Again this is purely my hypothesis.
Also, the service seems to vary area to area, from what I gather from some of the posts in this forum.
Spectra
I've shared my installation and other experience in this thread. Its been only 10 days or so since I got the connection, so far everything has been great. Its unmetered, so you don't have to worry about usage thresholds which I like very much, not that I keep downloading until it bleeds. The fact that you don't need to think whether doing something would cause you to go over the limit is very satisfying.
Connectivity wise, its been good so far. Couple of days back there was some routing issue where some of the sites weren't opening and was timing out, but was fixed before I could even open a ticket (maybe 30 min). Customer care is centralised and its in Delhi or Gurugram or something.
Also, I might be among the first few customers in the area (as they launched service very recently) so not sure if there would be any degradation once more customers are added. Have to wait and see.