I read several reviews about this console and it has a lot of problems (overheating, bad analog sticks, general instability, the usual not optimized firmware) so i decided to not buy this product.
RK3288 is a good SOC, i'm sure that JXD will implement this on JXDwhatyouwant, my concerns are about heating...i'm not sure if this SOC is designed for compact 7 inches handheld consoles.
JXD is no longer making new consoles, they are out of market. About q9, firmware is completely stable and no overheat in my device using last update. Analogs are pretty bad though, but I practically never use them.
The RK3288 is normally used in tvboxes, there are also some tablets using it, but Rockchip main focus is in tvboxes, and their SDK for tablets has less development than their Tvbox one.