Yeah, I generally prefer them when I've only got a couple of items, for that reason, especially if I want to pay by card for £1.50's worth of stuff. Where they really suffer is with duplicate items. The scanners evidently have a long timeout to prevent inexpert users double-swiping, so you have to interleave other items or sit there waving your thing like an idiot for ages.
They can be bloody tedious at 3am when they're in the middle of a batch job and all the database lookups take 30 seconds, though.