Digital scales are all pretty accurate and trustworthy. The vast majority will have a 'tare' (reset to zero without removing items) function. Always have a spare battery or a second set of scales in reserve, because one day the battery will decide to go too low to read anything, when you desperately need to weigh something.
I found a little glitch with my Aldi ones, though, while weighing out 5g of yeast for a bread recipe. I'd put loads onto a piece of paper before thinking "this can't be right." When I put a container on the scales, zeroed and re-added the same amount of yeast, I had way more than I needed. So clearly some digital scales need ballast, and don't perform at all well when the weight on them is close to zero.
Watch out for rice when measuring carbs. The Morrisions basmati lists the carb content as around 35g per 100g, when in fact it's more like 75. When you read the small print, the figure is for 100g of cooked product (where it's soaked up and added weight from water) but if you weigh it dry, you're getting the much higher figure. There may be other foods that soak up water during cooking that are labelled similarly.