Good to see there's some truth to the claims but at the end of the day there are two things to consider when deciding whether to pay more for a 904L replica:
1) Is it really 904L?
Just because one person buys watch model
XX' made by 'YY' factory from 904L and tests prove it is so, doesn't mean you or I will also get a 904L version. We don't all have access to metallurgical test equipment and will never really know for sure. It's not unusual in replica watches to not get what was promised. I have bought watches from TDs with eta 'swiss' movements - and upon opening the case back found seagull movements inside.
There is a thread somewhere where someone tested their 904L replica and found only the bracelet was 904; the case was 316.
2) Do you really need to spend more to get a replica watch made of 904L?
904L is not an expensive metal like white gold; it's just more salt water and acid resistant that 316L steel (which is why 904L is used in pipes that transfer acidic liquids). Aesthetically it looks, feels, weighs and smells no different to 316 steel. Any difference in appearance is attributable only to finishing.
Keep in mind that other high end brands (often much more expensive than Rolex) manage just fine without 904 steel.
What I think is more important in a rep than the steel its made from, is the quality and cleanliness of the movement, and the QC generally. I'd much prefer to put the extra money to those more tangible improvements.