I have used the older original Eichmann silver bullet plugs. They were nice, but over the years I have moved on to different materials. I have found that silver is not my preference for sonic signature. Silver is good for compensating for a system that is too warm, but it is very easy to go one step too far and then silver will push the upper mids/highs too much and the sound becomes a little artificial. It's a balancing act.
I would say ETI is great if you want a pure silver RCA. The Mundorf is likely better because of the 1% gold (it takes the edge off the brightness), but the Mundorf Mconnect silver RCA are $225 for a set of four (best price at Sonic Craft).
I have ultimately ended up with all Furutech Rhodium connectors. They can be very expensive, but they are the best. I have found that rhodium will have the speed and resolution of silver, but it sounds natural instead of pushing the upper mids/highs too much. If you don't mind soldering and want good no nonsense RCA, the Furutech FP-126(R) rhodium are $90 for a set of four from Parts Connexion or VH Audio. It's a basic non-locking RCA without set screws or anything fancy, but it uses the Furutech Rhodium plated OCC copper center pin (ground/shield is still copper alloy). The more expensive Furutech rhodium have more features, such as set-screw, locking shell, carbon fiber, etc. The ones with the set screw can be hard to get wires inserted because there is not much space.