I've done a lot of research on all these attenuators now and there's definitely no simple answer. Some of them sound better than others, some offer cab simulation, some have an FX loop. But there's none that does all of this - or even half of what the Kemper does.
The Kemper is still the ultimate recording tool, as it seems. Yet the downside remains that profiles produced by others are always just snapshots of what the real amp could offer. (I think that's also one of the reasons most of you guys still own tube amps as well).
For now I decided to keep my Kemper. Even if I only use a handful of profiles - and would love it if they'd be more flexible - I at least know that they work perfectly. Even more importantly - they're fun.
I think in my particular case it would be best to save up a little longer and get the amp I want, add an attenuator to make it manageable and then create my own Kemper profiles to be able to record with it as well. In this case I could also use said amp as a real cab to go with the Kemper, which is a bonus.