As far as gaming features go: Recon 3D has THX surround sound. Titanium HD has CMSS-3D. Z series has SBX.
I'm not sure if SBX is a rebranding of the THX effects. I haven't heard much of it. But a lot of people like CMSS-3D better than THX. Here's a comparison video:
http://www.youtube.com/watch?v=eiVbq0P00As
The THX stuff on the Recon3D is a re-pack of a large portion of the Creative branded features on the X-Fi, and reminiscent of the Audigy's "THX Console" more than anything else. I'm unfamiliar with the new Z series hardware, but Recon3D is certainly fine for music (I'll put it this way, compared to the last three generations of Sound Blaster, it was not appreciably better or worse - but of course we'll all keep repeating that "Recon is bad for music" because "that's the way it is" - and in another thread keep repeating that "all DACs are the same it's all the same ABX OR DIE!" :rolleyes
.
Recon dropped some of the overt h/w features that X-Fi had, but my understanding is that it has more to do with Microsoft's change of direction on Windows audio more than anything on Creative's part (Creative's claim is that the SoundCore is suitable in terms of processing power, but I don't think it's on-par with the original X-Fi for throughput (not that you uh, *need* that)).
I honestly wouldn't worry about the whole "which is the best" between the three, especially when the majority of the "options" are more or less the same card (Recon and Z are essentially the same thing with different hardware extras and depending on which specific models, potential changes to the board - but they're all SoundCore products; Fatal1ty is a marketing brand that exists for most of the X-Fi and SoundCore premium products, and you really won't get away from it - there is no "Sound Blaster Fatal1ty").
The X-Fi Titanium will have more obnoxious drivers (there, I said it), but is fine hardware in its own right. The SoundCore boards will have nicer drivers and equally competent performance, excepting overt h/w EAX support (but seriously, what *actually* uses EAX Advanced HD these days
).
Personally I'd get a SoundCore - if it's going to bother you that you can't be "hip" and have the Z (because the marketing woowoo tells us it's "superior"), get the Z, but the Recon3D is essentially the same board. I'd be critical of the current TOTL Recon3D (which costs ~$180 because it includes the worthless attempt at replicating the LiveDrive), and the current TOTL ZxR (because you should always be critical of the TOTL Sound Blaster, as they usually have more features than anyone needs, or needs to pay for).
Ok, I need help making a decision. What's better: a fiio e9 and excellent sound blaster card or fiio e9 and fiio e17 dac? Would they sound the same? What would be different? If I went with an external amp/ dac would I still get simulated surround sound audio like Dolby Headphone?
I think you need to re-evaluate your expectations. How are you defining "better" - better for who? In what scenario? What about next month? etc.
As far as sounding "the same" or "different" - that's a can of worms. The "ABX or die" camp will probably argue that they would be the same, assuming all of the EQ/DSP on the Sound Blaster was disabled, and I'd be inclined to agree that they'll sound very similar or functionally identical (in other words, I doubt you'll miss one for the other, unless you do an intensive A/B). The Sound Blaster will have a lot more features, and give you more expansion down the road, which is important to consider (imho) - but if you're of the mind that paying more for less features (so you aren't "paying for features you aren't using") makes sense, I can accept that (I still don't understand it, but I've seen the argument made enough times (usually with at least *some* foam involved) that I can accept there's no arguing with it).
Going with something like the FiiO will mean no Dolby Headphone, no surround simulacrum, no surround processing, etc. Because you're neither buying a licence nor a compatible hardware component. Like I said, less features.
Personally I'd vote Sound Blaster + headphones, but that's me. You mentioned the DT990 and K701 in the opening post; I have no experience with the DT990, but will tell you that the Recon3D's built in headphone amplifier (and therefore by extension, very likely the Z's built in headphone amplifier) will drive them just fine by itself; the E9 is fine too, but there's no need to spend more money imho (and IME the E9 has a terrible pot, while the Recon (like
all soundcards) has a flawless digital controller). Based on measurement data, I would assume the DT990 should be no problem either.
None of the boards you're looking at are approaching 10 years old, but I'll throw yet another wrench into the works and tell you that the Sound Blaster hardware that IS that old (Audigy family), would ALSO be just dandy for what you want, and the built-in headphone amplifiers they included (the true LiveDrive) will also drive the K701 (and a lot of other dynamic cans) just fine (and IME the pot is better than the E9
).
So tl;dr:
There's not nearly as much difference or bother as you seem to be making this out to be (and I understand being overwhelmed, and I also get that there's a lot of woowoo and madness preached from the highest peaks of the Internet), and I'd personally go with one of the SoundCore cards and be finished with it - it'll do what you want it to do (all by itself), and the drivers are less of a pain than the X-Fi "multimode" crap. If you really want tactile control on the volume output, grab something like the Sennheiser HZR-62 and throw it on the headphone output of the card.