Given hyperblades seem to be specifically aimed at releasing the actual Takara versions of things, I very strongly doubt they've gone and changed anything more than they would for a normal release of a Takara item - i.e. doing exactly as they always have because this is the normal way things go. Everyone is so warped by Metal Fury that they have forgotten Metal Fight and Metal Masters. Sure, there were small changes to things, but nothing so extreme.
Basically, everyone is way too worried about the MW's being different weights. We've seen that Flash is identical and Diablo seems to be within an acceptable weight range, and that all of them so far seem to look identical to their Takara counterparts. Everyone should just chill on that, assume they're normal, and if they turn out not to be, then consider it an exception to the norm rather than an indication thereof.
Of course, hasbro parts having slight differences isn't completely unknown, I mean, we had the wildly varying CS's (though maybe this was to emulate the different molds TT released, as unlikely as it sounds), softer rubber for many things (though Takara Tomy parts do vary quite significantly as well there), and some have mentioned the that their recent ED145's are smoother than their earlier ones - though I'm yet to hear from someone with even an old Hasbro one and a Takara Tomy one (if they are the same, then it is likely the new hasbro one is somehow lower friction, if the Takara one is better then we need to examine a possibly overlooked brand difference - though I doubt that's the case, given how eager people were to find such differences back when the part was released by both brands). So, comparisons of other parts between brands would be nice.
B: D however is a special case - the takara and sonokong releases vary so much (and seem to change in performance over time) that it would take an incredible number of samples to get a good average, and all of those samples would need to be done by the same person doing hasbro samples to get valid results... Basically, don't expect to be able to determine a difference in B: D even if there is one, however if everyone who buys one does 5 measured solo spins with it when they get it, then maybe we can get some idea of consistency at least. However, this will take a lot of time, and people should stop jumping on youtube videos of all things for evidence either way.
Comparisons of rubber feel between brands for appropriate parts is very helpful, comparative pictures and weights are as necessary as always (just no more than they were in Metal Fight/Masters), any noticed changes in design, etc. Honestly, I feel we need a thread that can have its OP actively updated to collect and discuss any brand-based difference, and once we're sure of them they should be listed in the OP (and it'd also be good if things that require confirmation were also listed, albeit in a spoiler to prevent confusion). Could probably go on beywiki once it gets comprehensive enough....