Your thoughts please

If the spade makes a solid connection it is no problem.

Bare wire is usually fine as long as it is 'clean' and does not get corroded.
If the connectors on your anp do not screw down very hard on spades, they certainly would still be a better contact than a banana.
Just because they are plastic covered does not make them bad.
And audio salesmen are not audio gurus...

I had a similar problem with my Yamaha M60 amp. The spades were too large because the connector were very close together. I ended up using bare wire and / or 'pin' connectors. Sometime I broke the pins if I screwed the plastic down too tight. Great amp, and the main reason I don't use it is because of the speaker cable connectors! That sucks. That's one of the main things I look for in amps now.

You don't need neither spades or bananas. Them only for convenience. For performance use naked wire.

Bare wire treated with a little ProGold to prevent corosion is best IMO.I have found that plastic screw downs do not stay screwed down on spades,they must constantly be re tightened.

@ Maraknetz: I have often wondered about this: "For performance use naked wire". In other words, the bananas or spades are simply for ease of use? I thought the ends made for a better contact but perhaps you are right.
You have to be careful though, when you say "You don't need neither" it is a double-negative which technically means you are saying that you need both! You don't need EITHER is what you meant to say! (I'm not the grammar police but I thought I should point that out!)

Simple math:

Wires connect to Spades or Bananas either crimped or soldered and than last connect to binding posts.

If no spades or bananas Wires connect to binding posts Directly with no additional crimping or soldering.

... Could argue with anything, but math that is always true and have to agree that double-negative is actually positive(ONLY if multiplied and NOT subtracted).

I had plastic screw-downs on my Sunfire SRA, but figured that base under them is metal and they're simply for color purposes. I removed them leaving only the metal caps which I colored with permanent marker and if I ever need to tighten stronger than hand-tight, I can use pliers or small vise-grip.

Sometimes, the simplest solutions are the best ones!
How is the resulting sound? Do you actually hear a difference?

After years of believing that (and implementing) spades and bananas were needed, I have gone back to bare wire with a little ProGold on the ends and feel this is the best method sonically.

Bare wire, if you can get away with it as proscribed above. You can also try tinning the lead ends with some solder, lightly applied, to resist oxidation and corrosion.

All the best,
Nonoise

I had some Anti-cables with spades. I got to looking at the spades and they didn't look so good, so I took them off and connected the bare wire ends. I thought the sound improved noticeably with the bare ends.

Also, FWIW, Morrow recommends their speaker wires with "nude" connections, if possible.