Forums are a terrific place to get a great number of opinions. Here is mine, the cost of which is nothing. Some might have the opinion, I'm overcharging.
My RimX is the finest rimfire I have ever shot. I also own a Deuce and have shot a Vudoo enough to develop a personal preference. I replaced the extractor on my RimX as soon I bought it ( used, the orginal had a small chip. it still extracted fine but you know what it is like when you have a gun new to you ). That extractor is now two years old with thousands of extractions ( hundreds of Eley ). The extraction has been flawless as have all the other functions expected. I cannot really answer your question regarding the Eley extractor but it is commonly believed that Eley has a thinner rim than most other manufacturers. With the perfect prescision evident in all other aspects of the RimX build I would not be surprised if the Eley extractor was made available in order to have a perfect fit with the thinner rims, as opposed to an attempt to negate a "problem".
Just shoot and enjoy your gun. You have one of the very best ever produced. Good choice.
Regards,
dgb