ICRAF/CIRAD's programme on Rubber Agroforestry Systems (RAS) has developed a serie of on-farm trials since 1994 in Indonesia in order to identify rubber based agroforestry alternatives to monoculture (SRAP programme). Three systems, RAS 1 to 3, have been successfully tested. Preliminary technical recommendations can be already released as most information during the critical period of the first three years is already known. Another RAS system, RAS 4, is suggested by another ICRAF team in order to test the hypothesis of a permanent RAS (PRAS) compared to cyclical RAS (CRAS such as RAS 1/3). Pros ans cons, interest for farmers in the short run and feasibility of RAS 4 is discussed. Information from previous observations are provided as well as a short economic analysis. The paper provides arguments and information on the relevance of RAS 4. The author thinks that RAS 4 can provide interesting technical data concerning competition problems of clonal rubber, in particular for the ecological model developed by IRD/ICRAF. But RAS 4 is not economically matching other alternatives such as RAS 1/3, rubber monoculture or oil palm as well as most farmers wish to move to more productive cropping systems. Playing the evil's advocate, the author try to give limits to researchers' dreams about systems sustainability and biodiversity conservation. This paper is voluntary very polemic.