Ionic's widgets aren't web components and aren't usable outside of Ionic/AngularJS. This means they're not recognized as custom elements by the browser (no future dev tools support). They leak DOM and CSS internals into the page. Worse, they require the host application to be Angular based.
Brick components are encapsulated, both with shadow DOM and scoped CSS, and usable in any web page and with any or no framework. You can freely mix Brick, Polymer, Bosonic, or "raw" custom elements in a single page.
edit: It looks like Mozilla is dropping X-Tag in favor of "vanilla" (what I called "raw") standard web components APIs. This would make Brick a collection of components, rather than a web component helper library like Polymer, and more akin the to Polymer project's Paper Elements.
Definitely, though when it comes to UI frameworks, many developers want a complete (and styled) solution, and usually stick to a cohesive framework. Brick is obviously more modular, but that's not enough yet. It still needs more components and perhaps themes in order to be looked up, but I recognize it's a new project. Hopefully, the exposure today gets it some contributors.
Not sure Brick is now "more modular" and "lighter", without X-Tag - in fact, it's quite the opposite. They've dramatically increased the weight of each component, and constantly repeat the same code over and over, much of which is derived from X-Tag's internal methods:
The above examples call into question the claim that the move was to increase modularity and decrease weight - clearly that isn't the case when you actually look at the code.
We (Ionic) don't use web components because they aren't widely supported on mobile (yet) and the polyfills have pretty hefty perf impacts. When that changes we definitely will.
Brick components are encapsulated, both with shadow DOM and scoped CSS, and usable in any web page and with any or no framework. You can freely mix Brick, Polymer, Bosonic, or "raw" custom elements in a single page.
edit: It looks like Mozilla is dropping X-Tag in favor of "vanilla" (what I called "raw") standard web components APIs. This would make Brick a collection of components, rather than a web component helper library like Polymer, and more akin the to Polymer project's Paper Elements.