The couch beds at Jambo (and Kidani) are adequate. Not as comfortable as a real bed but much better than the junk that passes as a couch bed in far too many hotels.
Note that as a whole, the 2BRs at Kidani are far better than those at Jambo -- 100 sg ft larger, three bathrooms, more closet space, a much better master bath. However, the desire to save points by going to standard might overrule having that difference.
Be aware that at Jambo 50% of the standards have pool view and the other 50% actually have savanna view -- in 2012 a large conversion was done to make many savanna view rooms standard rather than savanna view because the views were not considered the best, but most of those converted to standard view rooms actually have fairly decent savanna views. If you want to get standard at Jambo and try for savanna view, then a non-guaranteed request to make is for a room on the Kudo Trail side of the building -- all standards on that side have savanna view.
You do not say when you will go in 2021. Right now it is mostly pointless to stay at Jambo -- no open restaurants, limited service. How long that will last is unknown and it could last well into 2021 because even if a vaccine starts distribution in a few months, it will likely still take a long time before the World returns to normal.
