ive got the streamline 9.1kw heater its grate, i run mine on the warm setting most days as its plenty hot enough for sole trader ! the streamline is £6000 all in, i sent a message to ionic they said theres was about £5000 all in, the only difference in the too from what ive herd it the ionic one has a bleed off valve so it does not shut down when you turn water off at the brush , i opted for streamline as there 30 minit drive from me .