I have both AIS and 3bb fiber - AIS is 500/300 and 3bb is 1000/500. Honestly, they are both extremely fast and reliable and i can't tell any difference between the 2. AIS is slightly cheaper and comes with 15gb 4g per month and a playbox which i personally never watch. We are paying less than 500 baht because my wife is a long time AIS user, it's an incredible deal for what you get in my opinion. I used to have True and in my experience both AIS and 3bb are far superior. However, as other posters note it is extremely location dependent. I am in Sansai, Chiang Mai.