Is the speed test provided by CAIW Diensten BV sincere?

Hallo Guys! I have been using a connection by CAIW Diensten BV, Netherlands. Every time that I carry out a speed test I realize that everything is functioning well and the agreed speed. My biggest worry is that the speed test is carried out using a functionality provided by the same company like most other companies do. Are these tests accurate or could they be to hoodwink the user that he is having a really good connection? Please advise. Thanks.
