In a nutshell, ProofHub is simple but done well. Aside from its core features - custom reports, time-tracking, dependencies, in-app chat etc. - which all work very well, pricing is a huge USP for ProofHub. Large companies can get excellent value from their flat fee which does not depend on the number of users. However, note the flip side of this: ProofHub is exceptionally expensive for tiny teams with only a few users.
Communication and customisation stand out when using ProofHub. Communicating with colleagues is a breeze with an in-app chat, comments on each task, and an announcements widget on your homepage which displays any team/company-wide messages. Additionally, white-labelling, custom reports and editable homepages make ProofHub nicely customisable. However, ProofHub lacks any automations - a serious miss on their part.