I just changed the booster position and now I have full power for straight and quality signal , but my delta dropped from 11 to 5 . what is more important to get a better speed ? delta or straight and quality signal thanks
Delta is generally more important than Signal strength.
Delta is the difference between RSCP (Received Signal Code Power) and ISCP (Interference Signal Code Power). Interference is caused by a variety of things including other cellsites and, to a lesser extent, other users' Modems.
Your delta will directly affect the proportion of the data transmitted which is payload, and the proportion that is error correcting codes. The higher you get it, the better off you are. You can test the effect by using a speed test site. If you use the one at www.woosh.com/speedtest then there will be the least number of variables between you and the speed test site. However, both the figures you mention are good, so there may not be much of a difference.