Several years ago, I tried doing some research before buying a batch of disks (6 for me and another 8 for a customer) and found it difficult to obtain any real information about the differences between desktop and enterprise grade disks. I eventually opted for Samsung HE103 (1 TB enterprise disks) based on my great experience with the desktop variants I'd fitted to various NAS units (including my own ReadyNAS NV+). After asking a few questions via emails to Samsung, I was quite surprised when a Samsung engineer called me one day, and even more surprised to hear he was based in Edinburgh and thus only about 5 miles away! One question I asked was a out the weight difference quoted for the two disks which - from memory - was about 10 grams; I asked if this was down to enhanced mechanics and he indicated that was his understanding, but at the time, he couldn't obtain any written information to back that up (these were quite new at the time). Anyhow, we had an interesting chat and debated a few issues, but I suspect that with all disk manufactureres, the full information never escapes the design and testing departments due to the fierce competition between the various vendors.
In general, one thing I often wondered was whether enterprise disks applied more energy to reduce seek times (which I've always thought would make sense; lots of corporate customers demanding small files scattered across a disk would require the head to swiftly move to different parts of the platters) and when I read your post, I was wondering if that could have an impact on wear and thus be a contributing factor in the difference between load/unload count failure statistics between WD Red and WD SE disks (SE being fed higher currents and the head mechanism experiencing greater acceleration stresses), but that the WD RE shows 600,000 would kibosh that line of thinking unless they've specifically engineered that model to cope better than the others. Of course, there are no clues in the specifications (and the seek noise for all three is 3 dB above ambient noise, but that doesn't tell us anything useful as a small increase in acceleration performance might not make that much more noise).
It would be great (and extremely interesting) if the disk manufacturers released white papers explaining the differences between the models and their thinking behind many aspects of the design, but as I alluded to above, my suspicion is that the disk manufacturers have always operated in a culture of corporate secrecy and release the very minimum of information that they are obliged to release. If anything, it looks as though this is getting worse rather than better as specification sheets are 'dumbed down' into little more than you'd expect to see from a press release of an as yet unreleased new product.
Back to the Samsung disks and all these 14 disks I installed a few years ago are still going strong. 4 of my ones have been sitting in a TS-659 (my music server Qnap) and I've still two spares sitting in their boxes. Now that disks are available in such large capacities, I'm pondering moving from a RAID 6 Intel based NAS to one of the current ARM Qnaps with two good disks in RAID 1 (and leaving them spinning 24/7). I have always been weary of WD since the Green/Black/Blue issues (and have trust issues after reading the explanations given by WD) but having fitted a good few WD Red disks to customer Qnaps, I've been quite impressed. That said, this load unload issue (and the issue with disks being set with different parameters) makes me wonder if they're quite as trustworthy as they could be. I plan to look closely at the specs for the desktop and enterprise Hitachi disks before taking a decision, but it seems there are very few negative posts about these disks, so either almost nobody is using them, or they are just very good.
NB Sorry for any major typos; at the moment, I've no time to proof read the above ramblings and will thus have to do so later (and knowing me, there will be a good few).