I have been testing a number of providers but also testing links from sites where the links are posted free to investigate channel lineups and quality of streams.

What I quickly picked up was a number of streams simply restream the same provider of the stream and almost all use Xstream Codes Panel. From my research the panel allows providers to input links where they have channels and restream / pass through.

It was interesting the number of providers who were using streams from other providers and passing as there own HD content, some providers were streaming there own content but this was mainly 480p and not always the best.

What I now do is test IPTV providers not for buffer but stream is it a original or on exchange. As for buffer this usually points to a overselling of resources, simply too many people connecting to server and its coping but just about. Remember each server probably is using a 100mb shared connection or 1gb shared with others. The majority are based in France as a certain provider there provides cheap servers and bandwidth.

There are some good providers out there but they will lock down to MAC address and a lot who dont advertise publicly, they stream own content and dont have hundreds of channels but specific subs onlys.

Anyway this is what I have learnt and it may be useful, may not :)