@winlin I use System Mechanic, Kerish Doctor and Advanced SystemCare Ultimate (which I got as a giveaway) - but I don't use the registry cleaner in ASC as it is not safe to use for the time being (a future update should make it safe to use).
Very infrequent updates has been a problem with Baidu for several years now. One of the reasons I stopped using it about 2 years ago.