They are excellent plugs, just make sure to clean them regularly, if you let them go too long it can be hard to get the dirt off... the platinum plating doesn't corrode but it's not quite as dirt resistant as gold or rhodium.
I'd keep the WBTs, the difference between Furutech and WBT is very subtle. This was a surprise as RCA plugs can make a big difference and the design of the two plugs is quite different, so I expected to hear a clear difference but it just wasn't the case. I do add cf dampers to the WBTs which helps but it's not a night and day difference. If you're buying new, I do like the Furutech because they are more robust, they look better, they address vibrations better, and the plating is better in terms of being easier to clean and not having dirt stick as much... but in terms of sound quality they're very similar.