We have been doing baby led weaning (BLW) and have been really big on having the baby teach herself how to drink from cups, feed herself, etc. These cups are amazing! While my 8 month old child didn’t really understand it at first she finally got the hang of it and we no longer even use straw cups. We have had no trouble with leaking when the cup has been dropped. We throw it in the diaper bag and never have issue with spilling. We bought four so we have clean ones around at all times.
Tip: fill up as full as possible when first teaching the baby to use as they won’t have to tilt it as far up to get the water.