End of Life? Not quite yet! I picked up the DSX11 on Thursday. Mike had fitted a new gimbal casing plus RF check. Cost £31.00. He tells all clients and hands out data sheets on likely issues with RF. 2.4 ghx is very busy nowadays. He has said that it is paramount as TXs get older to complete a range check and ensure antennas are positioned correctly. And not shielded by servo cables, etc. Agreed in practice it is not always that easy on small planes - hence range check even more paramount.
Although with the DSX 11 down to 60 mw. theoretically assuming conditions are good you would still have control when it is just a small speck in the sky.
Footnote: Mike said that in the USA on DSM2 some were being upgraded (illegally?) to 1 Watt. 10 times more power than needed and useless at model airshows. That would washout nearby DSM2 which has to look for two empty channels. Hence the move for most radio gear to go constantly skipping. You want range? 900mhz the answer.