Demerara sugar vs. Barbados Sugar vs. Turbinado sugar

I think the topic says it all -

Is there a great difference in the final product when using these varieties of sugar? I know I can get turbinado sugar very easily, but I have yet to see Demerara or Barbados at any grocer/LHBS.

Would the difference be noticeable in small volumes such as under 0.5lbs in a 5 gallon batch?

It depends on the beer and the sugar, some of them are considerably darker and can give more "raw" sugar character. However, at .5 lbs I doubt you probably won't get much character from any of them especially in a bigger/darker beer. Ethnic markets are often a great place to go for interesting sugars.

The differences post fermentation are VERY Subtle aside from color contributions.

Most times you'll find the Demerera in the sugar aisle. Sort of a creamy tan colored product. And "Sugar in the Raw" is Turbinado sugar.

Hit an asian market or an Indian market for Coconut or Date Palm sugars. Those are nice as well.

Well I was planning to use one of these in a mild/brown ale, but still wasn't planning to go over 0.5lbs. So long as I avoid that cheap winey taste I am happy.

I've never seen Barbados sugar, but I've used Demerara in England, and Turbinado in America. I'm dammed if I could tell the difference between them.
At 1/2 lb in a 5g batch, I don't think you will get any off flavors.

-a.

Sorry to bump this again but I have one more question. Its getting close to bottling time for the English mild I brewed. I did find Demerara sugar at the local grocer so I was able to use it in my batch.

My last question is can I use this for priming and if I do will it contribute to more molasses-like flavours? Or do I run the risk of ending up with some off, wine like flavours and should just stick to dextrose?

No problem using it for priming, but such a small amount probably won't add much more flavor. Use slightly more than you would when using table sugar. Hope it turns out well.