I was excited about the cup adaptor. However, I am extremely disappointed that the black lid attachment to sip from is extremely difficult to open. Additionally like other customers have mentioned, it is very difficult to create smoothies in this cup adaptor. Perhaps a smaller less bulkier items e.g. making dressing is all it is good for.  I need to revert back to the larger carafe to make smoothies with frozen fruits as the ingredients do not get stuck and blend very smoothly.