They offer an available lifetime warranty on the arm for additional money. I dont think the single arm is where you need to be worried. They have been doing this mono arm long enough that, I think they have that figured out.
JCB has struggled building a machine that people want to buy. Their older machines were plagued with issues. They invested heavily in this new series. There is the one machine that Yellow Dog is referencing on here that is having issues and he is right, that does not condemn the whole lineup. However historically JCB has struggled in this market, partly due to building a shitty machine. So if you have a strong dealer that you know has your back if this machine turns into a turd, maybe I would entertain the JCB/Volvo. Just know that you will see twice the depreciation rate of an established machine. There is no doubt these machines are more safe than other skid steers. I can see some applications where that alone would sell the machine.