My personal experience:
1. Initially there will be no problems in your speed, connectivity, whatsoever.
2. Later, as half of the moth passesby, you will experience all the problems like gateway not responding, slow speed. If your gateway stops responding at 11 in the night and your cable TV operator(who also is your LAN operator) will open his shop only at 10 A.M. next morning, then no internet from 11 PM to next day 10 AM.
3. Your LAN operators use cheap-fragile hardware ( they call it a 'switch' ) that blows frequently. You will have downtime during this period.
4. To speak to customer care in sify, you have to waste 2 mins. of your time every time you call them in 1.Selecting your language2. Selecting you are BB or Dial-up user/ Choosing if you are existing customer or a new customer..4. Choosing whether you have a technical or non-technical quesry, etc.
Finally, they will play a hold-on music(may may be as long as 5 mins). Even after this long period of holding the call, at the end they will ask you to enter your phone number and disconnectthe call. They say their executives will call you withing next 24 hrs.
5. They don't provide refund for downtimes due to their mistakes.
6. Their engineers are incompetent(Experienced it myself). One engg. could not detect a break in my wire and had me get my LAN card and motherboard checked. I will not mention the pains I had to bear to carry it from from home to distant service center and then back to my home, only to find that it was working very well, and had no problems. Even my cable walla boy(whom I doubt if is even 12th passed) does wire check as a regular and primary measure while handling connectivity issues.
OVERVIEW:
If you have any other ISP in your area, Sify should be kicked.
Don't even go near Sify office.
They are the worst ISP I will ever see in my life.
After-sales customer service is terrible.
They are unrealiable for your business or home needs.
In my case, just because the cable-walla-boy was helpful, I didn't have THAT serious problems.
My current package with sify is expiring in next 2 days, after which I taking broadband from Exatt BB.
Sify is over-priced(not affordable), unstatisfactory in basic services, and horrible customer care service. Theis customer care guys know only good english. Their engineers don't know even that.