Of course Xecuter's dongle is a better dongle. Both the better capacitors and I suppose that the better design of Xecuter's dongle make the price difference.
That's the thing.
XKit's RCM jig is SO MUCH better than the SX Pro jig.
It slides in and out so easily, the SX Pro (which used to be the best jig) still requires quite a bit of force when you slide it in/out.
And yet the connection is still 100% stable and the success rate is 100% reliable.
So I had VERY HIGH expectations from XKit just because of that.
And just looking at the features... like being able to replace the payload just by dropping in the .bin file (no .uf2's or buggy flashing software), multiple payloads... it looks like they TRIED hard to be the best. They even used capacitors with "higher capacitance" than the SX Pro caps...
and I looked it up, this site says:
So the larger the capacitance, the higher is the amount of charge stored on a capacitor for the same amount of voltage.
So it totally looks like they tried to one-up all the existing dongles out there.
And I believe they'd have done it too, except they overlooked checking whether the charge was kept. And I think other dongles solved having their stored charge drained while not in use by having an on/off switch.