I used mine from a couple months after release until the 4S came out and have no experience supporting that - it was equivalent quality to any other phone I used during that period (pre-VoLTE). The main source of problems was AT&T's network but that affected all phones since it was do to them having massively underprovisioned their network.
(IIRC the iPhone issue was hypothesized to be related to an incorrect GSM power management implementation.)
I wouldn't be surprised if they tried to blame the phone hardware but given every other interaction with that company I would default to assuming someone got a bonus for “saving” money on network capacity and then had to play damage control for a couple of years. My previous phone only had sound quality as good as the iPhone because I had unlocked it and enabled the higher-bitrate standard GSM codecs which AT&T's default policy had disabled.
Also, the Blackberry was actually useful as a phone. IIRC the iPhones could barely make phone calls until the iPhone 4.