I love using click-bait-ish titles, right? This one addresses the year we're now in and "12" of course is referencing the version of HCL Notes and Domino which is currently under heavy beta testing around the globe. HCL just released the second iteration of it to the public. If you are not registered to the beta forum to give feedback then you should do so asap - it can only get better with your contributions.
Client or Server?
My personal preference has always been the server as the client is not an essential part of my daily work anymore. Our apps are all browser-based so I keep focus if they still work with new versions. Usually they do. HCL is keeping the credo of backwards compatibility. Here and there we face some issues though, but only with very special circumstances. I updated my Docker-based beta 1 Domino on my Mac during the webcast in 5 minutes - using this and this. I documented the process in detail for myself here.
To get an idea of what's in the beta 2, here's the fix list: https://ds_infolib.hcltechsw.com/ldd/fixlist.nsf/Public?OpenView&Start=1&Count=30&Expand=1#1
Controversy: the new workspace design
Man, even before the official presentation in yesterday's webcast from HCL we were able to get a glimpse of the new workspace (thanks to being an HCL Ambassador) that is enabled by default in beta 2. The discussions already went nuts in our Slack chat about it.
It's different - a bit. It lacks some functions we had before - a bit. Overall I do not see a huge improvement to what we had before. My first "natural" reaction was: how to set it back to the "traditional" design? There are 2 ways to get it:
- in preferences, you can always enable the "textured" design which bringst up the R4-ish tiles
- setting a notes.ini param Workspace_Navigator=0 brings back the 11 workspace design with the beveled tabs but with square tiles
Is it a deal-breaker? No. People will love and hate it like they did before. At least the new default wallpaper is much more decent.
Template re-design
The public directory got a new icon - the rest of the design remains R5-style (with extra options here and there according to new features of course). The rooms and resources database got a complete redesign, similar to the look and feel that the user's mail database already did with 11 and 12 beta 1 and also the new Certificate Store database that lets you enable Let's Encrypt SSL with just a few clicks - and without the hassle of using kyrtool etc.
It's cleaner and also more subtile. I see big issues coming for users with visual impairments as fields could not be distinguished as editable or not. We do not have the borders/brackets around them anymore. Very hard to tell for my taste.
Color schemes
In general I appreciate getting some facelifting but colors are not adopting very well in beta 2 - there is room for improvement. If you do not choose a background image for the workspace, you cannot see the tile texts very well.
Same for the replica button (which isn't a button anymore but just 3 dots). Trained users will spot them though.
Domino Designer - it works!
This was the first time I installed a fresh Notes/Designer/Admin package on a blank Windows 10 system (a test VM of course) without having issues with Eclipse-Home variables not set or unset plugin-dependencies. DDE worked out of the box. I always had this with version 11 (and also always got salvation from Jesse's blog post all the time: https://frostillic.us/blog/posts/2018/10/19/058650e080e352178525832b00519d2c). I didn't spot anything about this in the fix list, but hey, I call this a plus.
Speed!
I don't know what efforts were made to improve the overall performance of both the client and the designer, but 12 is so much faster than 11 had ever been for me before. It starts faster and DDE renders faster - I would say round about 300%. I hope there is nothing missing now 
Instead of using DDE 11 I am tempted to use 12 beta 2 now for development.
Resume
There is more to come, beta 3 is around the corner already. With beta 3 we will see a basic Notes client in 64bit for Windows - which is great and long overdue. I fear we will never get rid of Eclipse as the base for the standard client nor the Designer. Well...
Again: participate in the beta testing and give feedback in the forum, it can only get even better!
See also Hogne's summary here: https://ncug.org/2021/02/16/fake-news-about-notes-and-domino-this-is-the-real-news/