Based on the collective experience , every manufacturer has better and weaker series (actually, manufacturers produce only few types due to production optimization, and then sort them in tests to see which piece gets which label): of the WDs, Gold, RED and RED Pro are the most reliable, most frequently those (Green and Blue) dies out of all WDs whom designed for office work (just 8 hours a day, only with few on / offs), with Purple falling between the former two groups. In my servers e.g. I only use REDs (32 of them in the last 8 years) and none have ever died before (OFC I disabled the agressive head parking and they're on UPS).
Seagate far worse than any WD despite of the fact there is a typical WD and Seagate HDD disease, a slowdown (named "slow responding issue" - usually it has one or more weak heads and the resulting unstable / bad sectors that are diligently collected by the firmware and this slows down the drive - i.e. the firmware overrides certain processes - like read / write operations - because sector list data cannot be updated), what is the first user noticeable sign of the dying drive: weak heads constantly developing bad sectors, if one or more of them in the disk's Service Area named "SA" (where the neccessary informations stored to up & running the drive itself), various problems can occur. When they start to slow down noticeably it means their end, because under the hood, only the "chewing gum" holds them together: they are probably full of bad sectors, but the firmware can still replace them from the spare area for a while. In this case (using home methods), your drive can't stand a full user data area backup. If the drive has not stopped completely, with special software like PC3K can be used to disable the weak heads and turn off realtime error-correcting background processes, thus speeding up the drive, then with the good heads can make a disk image copy of the sectors covered by them at normal speed, and then by switching the faulty heads back on, one can also try to save it's sectors. Thus, by putting as little stress on the drive as possible, there may be a minimal chance of recovering the data without breaking it and replacing the head block (because that would make it significantly more expensive - unfortunately, the heads have often been degraded to such an extent that the replacement cannot be swept away).
HDDSuperclone (it runs in Ubuntu too like DDRescue) has script to manage WD's slow responding issue, but sadly not working on newer drive families.