I have a set of 80s G12-65 8 Ohms in a reissue WEM cab, the one brain theory tried out, and they sound really great. I then bought another WEM cab and installed a set of reissue G12-65 16 Ohms in it, and it sounds incredible too. A bit different, not drastic, but it's there. The cab with the old ones have a hair more mids and low end.
Keep in mind that the two different cabs, even being the same brand and model, are going to sound different. So are the speakers, even if they are the exact same model. So, there are batches of the 12-65 that might sound a bit brighter, and some that might sound a bit darker. That's why you'll see, at some studios, a 4x12 with the exact same speakers, but with a tape on the back with the following instruction "Use top left!!!", or whichever is the speaker that sounds best in that cab.
That all taken in consideration, I really like the reissue speakers. Are they my all time fave? No. Are they great enough for me to enjoy them? Hell yeah!