I don't think Cowons offer "SRS", they only offer "BBE / BBE+". BBE are basically sound enhancements, which are separate from Equalizer (EQ). Read more about BBE here -
http://bbesound.jp/img/tech/What_is_BBE_English.pdf.
One counter-point in favour of Cowon - battery life. It claims 55 hours, but manufacturer specs are for 128kbps under ideal testing conditions. In normal usage, you'll get 30+ hours with 320kbps. I've never got around to measuring the exact battery life because I get tired waiting for it. That's one of the reasons why I still keep my Cowon S9 around as none of my other players match it in that regard.
I'd suppose Fuze+ will not be as bad as the Clip+ and would provide close to 20 hrs.
Second could be a small difference in output power. Sansa does not seem to release the specs, but I am guessing it would be lower than that of C2. A few IEMs, which are hard to drive will be benefited by this.
As for UI, if Cowon C2 gets it's fair share of supporters, it will get a nice UCI which can replace the stock 'life style' UI or whatever they call it. Fuze+ will get Rockbox eventually, which will give plenty of options and a very good EQ to play around with. I actually prefer the EQ in Rockbox as opposed to the Cowon, though both work well. All this "EQ" fame of Cowon is from the past. Even iPods have eQu and Equalizer apps to compete against the Cowon. So, it's not as unique as it used to be.
I am still waiting for them to deliver a true successor to J3. Only then I'll upgrade my S9. I was in a dilemma over C2 at the pre-order price (7900, I think) mainly due to the battery life. But, it didn't make much sense to buy yet another player :ashamed:
If you go for Fuze+, buy a microSD card with the saved money - 16 GB microSD card (Class 2 / 4 - not much difference when listening, but better to go for Class 4 as it offers a speed difference when copying / library refresh. Higher classes would be a waste of money), fill it with music and then come back here to ask for better IEMs / ear buds / headphones.
If you go for C2, play around with the presets, EQ and all that, then do the same as above - only this time go for an IEM first, then get the uSD card.