But did you know their closest spiritual ancestors were made by Quantum Corporation, rather than Seagate itself?
I'm referring specifically to the Quantum Fireball EL, EX, CR & CX; mainstream 5400rpm drives with best‑in‑class performance and reliability (mechanically at least…), beloved by OEMs (then) and collectors (now) alike. In common between IBM, Quantum and Seagate (back then) was that their healthy (and lucrative) SCSI businesses could subsidize their ATA divisions (especially during hard times), maintaining their quality standards even while Maxtor and Western Digital (with little or no SCSI share, hence compelled to stay profitable in the ATA market at all times) slipped significantly.
Quantum strived hard to overcome the Fireball ST & SE's weaknesses, and although BB, the EL/EX/CR/CX still seem to outlast any HDD you can buy now.
(The Barracudas, given good electronics, outlast any other HDD ever made

Just by comparing them physically to the Barracuda ATA IV through 7200.8 (and debatably also 7200.9/10), you can see the family resemblance:
Both have sturdy stainless-steel covers (2-layer laminated austenitic on the Fireballs; an austenitic cover with adhered ferritic damper on the Barracudas) for robustness and acoustic damping, along with substantial powder‑coated base castings (to seal in stray particles and resist corrosion); both have high‑quality breather filters; and internally, Seagate adopted Quantum's famous AirLock® safety latch, which allows the heads to unpark gracefully (rather than the strong pulse required with the more‑popular magnetic stopper) and also provides superior non‑operating shock protection, in that no amount of shock can overcome the latch (without being so severe as to break the heads anyway) and dislodge the heads into the data area.
And while the old Quantum ProDrives are infamous for sticky rubber stoppers, Quantum learned their lesson quite promptly – all the proper Fireballs (the 4500rpm “Fireball TM” was really just a revised Sirocco, although even there only the 1‑platter variants used rubber) have hard plastic stoppers for long-term stability.
(That's more than we can say for the AVVN-series 120GXPs and their single-platter successors – those still used low-grade rubber

In fact, the relationship runs even deeper – both the Fireballs and Barracudas are known for being far more prone to electronic faults than mechanical failures (unless abused), particularly in that each line alternated between two manufacturers for its motor drivers – one reliable (Panasonic and Texas Instruments respectively) and one iffy (Philips, STMicroelectronics). Thankfully, however, both lines are also very forgiving of PCB swaps (different capacities are no problem, as long as you match the series); and what's more – of my three Fireball CRs (2×4.3GB and 1×6.4GB), the 6.4GB unit was benchmarking below‑specification in its first zone, although the remaining zones were clean. I swapped PCBs with one of the 4.3GB units and now it tests perfectly

But at least the Panasonic AN8427FBP and Philips TDA5147BH have the decency to be pin‑compatible (unlike the Texas Instruments SH6950 and STMicroelectronics SMOOTH


I've just succeeded in doing so myself – using an AN8427FBP from a dysfunctional (read channel?) EL to repair one of my CR's PCBs.
Of course this is all history, relevant only to those still running retro rigs; after Seagate sunk, I turned to Western Digital's Caviar Blacks as the next‑best substitute (reliable drives with 5‑year warranties at reasonable prices; and best of all, they were available in the full capacity range).