Oof. I suspect it's going to be a long day at MumsnetTowers....
I don't hate the overall new design which is much more modern, and has some great improvements, such as the rich text editing - no more need for tortuous formatting and link creation. I was also excited that not only have you added all the standard emojis, but you've kept the traditional mumsnet emojis - right up until I tried adding them to a post, at which point I repeatedly got a very threatening full screen error saying I don't have access to mumsnet.
I don't see threaded discussions - is this supposed to be an option? I hope it's part of the upgrade.
I'm seeing a bunch of bugs or design fails - why are my posts in green, the same as the OPs? Apparently I could change it but why do I have to... and if I have to, it would have been helpful to receive an email telling me about this.
In fact it would have been useful to have an email letting me know the site would be down for a few hours while you upgraded - or at least a banner on the site a few days ahead with the outage info. I imagine most mnetters are going to be unnecessarily blindsided by the change, which could have been avoided.
When I'm looking at my 'I'm watching' list, none of the links to individual posts work; I can only go to the thread title. I used to be able to look at the most recent post and go to that, which was an important feature.
Lots of other little quirks that I'm surprised passed testing :-(
I'm v enthusiastic about the change in general, but there are many more QA tests required.