Sucralose is as close to sugar as scientifically possible. It basically is sugar. The molecule is reversed. It taste like sugar but it is lighter and the body passes it right through with no ill effects. It's actually made from sugar.http://splenda.com/page.jhtml?id=splenda/faqs/nocalorie.inc#q1
In baked and cooked goods it taste the same, but in beverages you can tell the difference because it has a different texture and weight. This difference in texture and weight changes the flavor in liquids somewhat, especially hot ones like coffee.
What do you like to sweeten beverages with and foods with? Are you worried about potential health impacts of your choice?