If people write like this then it would help to decide which test series should be selected. Whatever you have felt about various test series, you have written it. If we have to compare things then we should try to give as much as possible information (if we have). As it is already mentioned that test series is for time management and know about the weak areas, so, according to me, people should have to take as many as test series possible to manage time in exam but make sure they don’t take wrong concepts or half information about something and for that many Q&A sites like stackoverflow, math.stackexchange, cs.stackexchange, gateoverflow etc. are there to help.