I think all the 5 series since the E39 have got worse.
E60 was ok, bit weird but it's not too bad, interior lets them down more than anything. Personally not a fan of the noise the V10 made over the previous S62 V8 but that's just me, an engine in such a car should soothe your ear rather than attack it like bees. Then theres the debate of the diff thumping SMG they had...
All the new ones, whatever the chassis codes, are just massive 7 series with dozens of M5 badges, and run click button automatic manual gearbox. Yes they might be hugely fast and full of fancy computers... but why is that good, especially when it comes to age and longevity, or the simplicity of fun?
I think true enthusiasts can see the purity of the E39 M5 as the last great M car, Doug got it right, it's just the right blend of old and new. Classy styling, not over the top, real manual gearbox, tried and proven technology. Plus, 400hp and 500nm is plenty, and it's an amount you can use in the real world.
It's also worth remembering the E39 is basically the same size as a new M3. It's all gone wrong in the new era!