Not regularly, but often.
There IS a HUGE difference, not just in taste but how you feel. Recently I switched over to not drinking soda (unless I'm mixing drinks, but that's another story) and drinking at least 2 litres of water a day. I feel better, I'm not as heavy (from a little over 150 to less, not sure as my scale isn't working right now) and I'm generally better off.
With organic foods, the premise is no preservatives, no artificial crap. For example, a common chemical found in soda and snack food is high fructose corn syrup. A quick few quotes: "HFCS has the exact same sweetness and taste as an equal amount of sucrose from cane or beet sugar
but it is obviously much more complicated to make, involving vats of murky fermenting liquid, fungus and chemical tweaking, all of which take place in one of 16 chemical plants located in the Corn Belt."
"When sugar is given to rats in high amounts, the rats develop multiple health problems, especially when the rats were deficient in certain nutrients, such as copper. The researchers wanted to know whether it was the fructose or the glucose moiety that was causing the problems. So they repeated their studies with two groups of rats, one given high amounts of glucose and one given high amounts of fructose.
The glucose group was unaffected but the fructose group had disastrous results. The male rats did not reach adulthood. They had anemia, high cholesterol and heart hypertrophy--that means that their hearts enlarged until they exploded. They also had delayed testicular development."
Read up:
The Murky World of High-Fructose Corn Syrup
Organic food? 
