The Google Pixel device line is the epitome of an "Android" device, it is the universal standard reference, made by Google (who develops the Android OS), using "pure" Android with Google's application suite, and they are kept up to the latest release and security patch on a monthly basis. It is the basis for all other Android device's operating systems. If an Android application will work on any device, it will work on a Pixel and they are the benchmark development device for most software developers. Half of our techs use Pixels just because they are so reliable and consistent, you will have no issues with MiCollab Client or any other application because of the device on a Pixel.
The only issue you MIGHT run into is it being too new and having compatibility issues when new base versions of Android are released since Pixel's get it first and usually by months compared to most other phone manufacturers, because Mitel (or other manufacturers) haven't gotten their software up to date yet. Many of our techs use Pixels (and the Nexus devices before that) and have never really run into this as a problem though, but I have heard of it with some other applications.
Google devices are the Android "standard reference" device. Honestly, I won't own anything else anymore.
