I do it myself so yeah I'd say its worth it. I've not tried it at such high power levels, I haven't any planars to drive. The sound of a pure classA amp where trouble has been taken to reduce the power supply noise is my reference - I haven't heard better dynamics from anything else.
Note that simply biassing for classA without taking care over where the load current is going won't necessarily deliver the same sonic benefits. In my understanding the reason a classA amp sounds better is because it generates lower power supply noise than a classAB. But if you want to go all the way to the lowest possible power supply noise you need to connect your load so that the active element (the darlington in my earlier schematic) is acting as a shunt. Plenty of SE classA designs arrange the current source to shunt the load - this isn't optimal in my estimation.
Note that simply biassing for classA without taking care over where the load current is going won't necessarily deliver the same sonic benefits. In my understanding the reason a classA amp sounds better is because it generates lower power supply noise than a classAB. But if you want to go all the way to the lowest possible power supply noise you need to connect your load so that the active element (the darlington in my earlier schematic) is acting as a shunt. Plenty of SE classA designs arrange the current source to shunt the load - this isn't optimal in my estimation.