In the July 2018 edition of the UK based amateur radio magazine 'RadCom' Mike Richards wrote up a review of the RSPduo. This review is now available for free to download from SDRplay (pdf). The RSPduo is the latest product from SDRplay. Unlike previous models the RSPduo has two tuners on board which can be used to tune to two independent 2 MHz wide areas of the spectrum simultaneously. It currently retails for US $279.95 + shipping.
Mike's review goes over the design of the RSPduo and discusses it's dual tuning capabilities. He mentions that the most exciting prospect of the RSPduo is going to be the phase-coherent applications, such as active noise cancelling. At the moment no software for these applications is available, however SDRplay is working on it. In addition to this, Mike also discusses the new API, changes to the filtering and connections, and well as some notes on sample rates and decimation.