I plan on ordering the 2013 iMac with a HDD. The HDD is a mature technology and the SSD is not. I am then going to add an external SSD: not only can I get a faster and less expensive one but when better ones are on the market in a few years I can upgrade (and/or replace when it eventually fails).
So the only question is fusion or HDD/SSD. I prefer the latter. Not only because I like controlling what is where but because if one drive fails I can use the other for everything (I will install a system on the HDD as well) until my latest backup gets restored. That would be something I could not do with fusion ... worse because BOTH drives would be corrupted.
Kara, I have seen multiple of your posts describing your direction... primarily because of the immaturity of SSD technology. While I will acknowledge that their can be several advantages to your approach... I personally think your distrust of SSDs is somewhat over-paranoid. I am very involved in SSD (and beyond-SSD development)... and the consensus, is that they are generally more reliable than the HDD technology they replace. I am not trying to change your mind or your direction... but rather offer the contrasting view for others reading this post.
The current iMac offers only 3 types of storage options, internally. You cannot officially get a SSD + HDD dual drive set-up unless you install a SSD drive yourself with the HDD only option...or use a Fused drive.
1- Hard Drive only 1TB or 3TB
2- Fusion Drive 128GB SSD + 1TB or 3TB drive (you may be able to "break" the fusion but could cause issues with your system)
3- SSD only 256, 512, or 768.
With USB 3 and Thunderbolt I'd highly recommend SSD Only.
Option 3 is my favorite as well. It does come with the added complexity of managing your data across multiple drives.
My specific recommendation is to buy a large enough SSD to contain OSX (and also bootcamp partition if desired), and also large enough for 100% of your primary data except for streaming media (video and music). Photos are a grey area.
I think that streaming media gets very little value from being on an SSD, and typically, streaming media is one of the largest consumers of storage capacity. Hence, it is perfect (from a $/GB standpoint) for streaming media. Additionally, keeping streaming media libraries (iTunes, iMovie, FCPX, etc) are trivial to keep on an external drive.
Photos are more complex. Light users of photography can probably just keep them on either an SSD or HDD. Pro users probably need large external arrays which today are primarily HDD based. In between "prosumers" like myself (400GB Aperture library)... need to make a choice of HDD or a pretty expensive SSD upgrade.
Personally, I went with the 768GB... but I could have also gone to a 512 with my library on my Pegasus TB array. Part of my rationale was than within 2 years or so, this will be my wife's primary machine, and I know that 768GB will be enough for her to be 100% SSD.
/Jim
