Slow to Load Bios, failing system?

also, if this is the wrong section for this kind of question, let me know and i'll repost elsewhere. well either that, or a mod can move it, that works too.

as an additional side note, my system appears to run absolutely fine for extended durations of time, no random crashing or slowing down, at least as of yet.

The two main factors that slow down the computer at boot are:
1: PSU
2: HDD

Since you have already had problems with earlier HDD's this indicates a major fault with you PSU not being able to supply the HDDs with the power required.
Before you do anything or end up buying something else, just borrow a PSU or if you have an extra one that gives 1200W use it .
The 285's are heavy power users , plus the rig itself is pretty power hungry....
Next you need to install some utility to check the HDD, not the platter and stuff like that but the data cycles or life expectancy or something like that,
I remember having such a utility long time back but don't remember the name , but it gave me a lot of data about each and every HDD connected and working with the rig. I think it was HD Tune or something like that, I actually remember installing it for temperature purposes....   but the rest was all a bonus... could be passmark or more recent was the Crystal disk info....

Check what is wrong thru it and compare the results with other drives

You say it is too slow getting through the BIOS POST, and report, "It'll 'spin' up, so to speak, but won't make it to the bios loading screen for a while. " I'd like more exact details.

What I normally see when power is turned on is, after a brief few seconds the screen first shows some data on the BIOS version itself at the top of the screen. What is not "seen" is that, in those first few seconds, the BIOS does a few basics checks on itself and then checks the video output device (built-in or video card) because it cannot tell you ANYTHING with no video output. So if you do get that first phase of the POST process on screen within a few seconds, that part is OK. If it is taking longer, either the BIOS itself is having issues, or the video output system is having trouble. How long does it take before you see that first text stuff at the top of your screen?

The next phase of POST is the RAM check (some systems' BIOS' have been set to skip this.) On mine, a counter rapidly increases to show RAM the test progress until it reaches top of installed RAM. Does yours do that?

AFTER that is when the POST process attempts to use various mobo devices and then the hard drives connected to its controllers. If the very long delays you experience are during this phase, it is possible the problem is with the hard drive unit(s). In my system I see a display of information about those hard drives, and then there is even more stuff continuing on about other system resources. After that my system (yours may not do this) gives me a pause of 8 seconds so glimpse the screen and choose whether to push the correct key to enter BIOS Setup. With no input from me, it then begins to load the OS (Windows). That marks the end of the BIOS POST process - from here on it is all OS loading stuff.

From what you say, all of your delays are in the BIOS POST process - is that confirmed? Exactly when in the sequence do the long delays happen?

Turns out that, after I posted, over the next few days the load times and consistency of loading for the computer degraded significantly, until the machine failed to post at all, was stuck in this perpetual cycle of prebios testing of fans. Looking around the forums for alienware, I saw several people that had had similar issues (in terms of failure to post) and they had resolved the problem by replacing the motherboard on the system, something I had been considering anyways, based on, what i perceived to be, mediocre quality of the stock motherboard. After doing this, the machine did, in fact post again, albeit slowly, but other symptoms which had previously been intermittent became more of an issue, leading to the conclusion (after a fair bit of time spent isolating the various probable causes of said issues) that the PSU was the main problem. It explained the hard drive issues that I had been experiencing, some of the optical drive issues that emerged, and the prepost hangups. New PSU is on the way as we speak   We'll see how that goes!