My taste experiences pretty much match those of
entropy in posts #9 and #16.
And without being too clinical

I notice a slight 'digestive system' change when I went through a few 12-packs of DC-Sp that I picked up a few weeks ago when they were on sale ($1.99 per 12-pack plus $5 rebate on 5).
The other thing to keep in mind is that the expanding variations of Coke and Pepsi et al are part of the battle for supermarket shelf-space. Every new variation of a Coke product offers the chance to displace a Pepsi product on the shelf (and vice versa).