So for me, Windows 8 is faster every which way, but spinning disk drives will seriously slow you down no matter what OS you're using. I've tried 7200 RPM drives and they were only marginally faster than the slow, tortoise-like 5400 rpm drives. I've also tried Hybrid SSD/7200 rpm drives and they were somewhat faster again than the 7200 rpm spindle-only drives but still tardy. However a full SSD drive was about 5-6 times faster than the Hybrid drive (I measured these with the free ATTO Disk Benchmark). And the SSD wasn't too expensive on eBay (and getting cheaper all the time).
My system is very complex, a lot of development tools and services which take time to start up. Win8 does not boot any faster overall, just the Metro subsystems load first. That you can get to Firefox quickly is irrelevant. Try loading SQL Server and a bunch of other utilities that require start-up processes and you'll see what I'm talking about. A development box like mine is simply going to take more time to cold start, that's all.
Once Win8 is up and running and all services have settled down, yes, it's quite fast. Whether it's faster than Win7 I'm not sure but it doesn't really matter; it's plenty fast enough running on an i5 with 8GB of main.
Sure, SSD's are going to speed the process up - of course: they're memory based instead of rotating storage. When they come out with a SSD that can replace my 1TB hard drive without breaking the bank then maybe I'll think about it. In the meantime this one is fine.
I find that the Windows 8 start menu comes up very fast after login, but nothing is usable until all the background processes have completed, so the actual start-up time is really no shorter than for Windows 7.
Yes, I can see how you would remember that as the OS was new and I had not hit the little parts that frustrate me yet. To be fair, there are a few things about Win8 that I love (file transfer interface, integration with my Windows Home Server and Windows Phone 8, etc... I just get a little frustrated at the things that M$ missed... I vent at times, just ignore me...
Lotus Notes 8.5.3 also starts up very quickly for me, yet it has a large startup overhead under the Eclipse framework, but of course YMMV.
I'm not concerned about the performance of the hard drive in this box. Once the system has settled down everything performs fine. My primary machine is a notebook (Inspiron 17R). I don't think there's a drive bay in there for a primary SSD and secondary hard drive. I have a 2TB external USB drive for backups and offline storage. A SSD would be a luxury at this point that I really don't need.
I think the 17R has one drive bay, the Special Edition may have two. The XPS 17 has two.
My old Studio 1737 (C2Duo) has two drive bays, SSD in one and HDD in the other. The SSD made me hold off on an upgrade, it's very fast now and have been getting up to 7 hrs battery life.
If they'd just come out with a 1TB SSD that I could swap this one out with (and not break the bank in the process) I'd probably consider it. However ... it's fine as it is.
I am by no means a PC expert. I have been using PC's since Windows 95 and have used every version of Windows with the exception of Windows Vista. The bad press concerning Vista (at the time) kept me away from it and in hindsight, I'm glad I stayed away. I was reluctant to give Windows 8 a try because of the bad press again; however I wanted to take advantage of the 'upgrade before Jan. 31, 2013' deal for such a great price, and I am glad I did. With a few minimal steps (i.e. getting a third party START button), I say I am using Windows 7 (formerly my favorite version) that has so much more power, options, and versatility and it is called Windows 8. I won't post anything negative about it in here because it seems everyone else has that covered. I like it, I'll use it, and it works for me!