A few observations after a bit of use:
1. the feedback button (question mark bottom right) doesn't work. Click, and nothing... using MS Edge latest version.
2. as someone mentioned already - the content doesn't resize to the window. on a big(ish) screen this leaves a lot of wasted space left and right. Tables get cramped when they don't need to be.
3. column types - please increase these. particularly please include the Lookup type so that we can relate tables.
4. files picker using @ symbol. This is great if you know the file name, but if you want to browse it's not good. Clicking the -> icon doesn't lead to anything. Should that lead to a files browser?
5. guest access. please make this seamless. So many orgs collaborate with consultants these days, please don't make that awkward. If so then more people will move to Google Workspace.
5.1 please allow guests to be chosen in the 'People' column type. This should be possible across M365 but for some annoying reason it's not.
It's a fantastic product - well done team! you are the model to follow for the rest of Microsoft!