G2 reviewers give PubNub strong ratings overall, averaging 4.3–5.0 across segments, signaling solid satisfaction relative to cost. However, pricing is the most frequently cited con across G2 reviews of PubNub, appearing in feedback from small businesses, mid-market, and enterprise users alike. Recurring phrases include pricing that can "sneak up on you," costs that are "high depending on use case," and difficulty debugging what drives transaction volume. Enterprise G2 users specifically flag opaque billing tied to presence events. Despite cost concerns, most reviewers retain PubNub for its reliability, scalability, and developer productivity gains — framing it as a premium investment that justifies the spend for teams with real-time infrastructure needs.