Why do they call them spades, When there so odviously forks? And why are the ones you could use as a spade called lucars? Its a mess.
I dont terminate cables at the amp either. Im an electrical test&inspection engineer, and would fail such terminations expecting to work at the loads we want to have them adequate of. There is no deformation. How ever tight you think it is, its just a tiny turn from dropping out. I cant actually think of a single application where this method of termination is acceptable except in signal wires. Even then there is some deformation. There is inadequate clamping force for the load. I guess if you bend the spade so the binding post has to flatten it then your trying but i like my binding posts to bind on some cable, not just stop. Its not as bad as the tilt ive put on it, but im sure you can see my point. Its adding something that can only do harm, and im expected to pay for it.
Im not so fussed about the mixing matterials arguement. Ive sat with half a dozen commercial phono cables and half a dozen professional audio wire lengths auditioning then along with a good few different phono plugs and found the plugs did nothing with £300 components. All the wires were different ofcource, but plugs didn't do a sausage. Its a tiny part of the equasion, like the generally rubbish wire used inside £300 amps to tie the posts to the board. As long as your connector is gold, its going to be the best conductor in the chain at all frequencys.
iirc surface oxidation messes with hf performance, and even oxygen free copper will oxidise where its exposed. Its nigh on impossible not to expose some though. At least without termination you can keep chopping the bad bit off. How many of us regularly dissconnect and clean everything anyway though?
Im also on silver plated stuff. Ive not heard a great many cables but the silver ones have been better than the copper. Im yet to hear gold but may make some phono leads to see. gold leafing the circuit board though... oh the fun.
To sum up. More harm than its worth. sprung banana plugs though... There good for swapping speakers regularly. They dont fit my arcam though. Arcam have there own termination system. Banana plugs are as good as banned now due to them fitting in euro plug sockets, as do pins and needles and anything else under 4mm. Its silly...