In the free version, your team can include up to 10 team members, who can collaborate on the project. In the paid version ($12.95 per user/month) the limit is 30 users.
If you save and the name you give has system weird characters like :, <, >... it'll simply refuse to save and do nothing (you'll have to give a name without those characters first).
Saving to cloud is broken in many cases
Merge down layer with mask changes actual rendering (workaround: first apply layer mask)
...
There are ads on the main page of the site, making for a less than stellar fit on screen. This can of course be countered by using an ad blocker in ones browser, though this does not work when using the Chrome Web Store app (which is the same as the site) as adblocker's do not work on Chrome Webstore apps.
At a high level the interface is organized into broad groups of tools called workflow modules. Modules like "Library" for asset management and "Develop" for manipulating the photos. Each module displays only those tools that are needed for that task. This allows you to separate concerns between tasks and reduces interface clutter. When you're, for example, developing the image, you're not bothered by interface tools relating to exporting it.
Within each module tools are grouped in a logical manner. Develop module, for example, will group tools relating to basic image adjustment, lens correction, and effects.
And there are a plethora of keyboard shortcuts that improve the workflow speed even further. At all times you can easily navigate between images you're working via arrow keys, quickly compare images before and after making edits with \, or see side by side comparisons with y.
Lightroom allows, for example, organizing images based on folders, color labels, flags, rating, keywords, GPS location, it can automatically create smart albums (albums that automatically update based on set rules) and it can be set to automatically backup, rename based on set rules, apply default processing, add keywords to images on import. It offers that functionality in an intuitive way and allows extensively customizing layout, behavior and workflow of managing assets to better suit your needs.