But it raises a question for me, why is syncing so hard on the HD? Blockchain is about 250G, that's only a few minutes for a SATA6 drive
Sequential reads and writes are not important. You should be more concerned about input/output operations per second (IOPS). HDDs usually reach ~75 IOPS while SATA III SSDs can go up to 120000 IOPS or more. NVMe SSDs are even better in this aspect.
So sync performance could be improved if the wallet would cluster the read/write operations. Not sure if this would be possible, I never looked at the wallet code.