I've got two currently. As you can pick these up for £20-30 they are great value. Halos use eyes in the ffedneck and can be picky about paint, not working with some colours. As every gun makes a sound when you fire, this is a more secure and reliable method.
BTW, this is a force feed loader - the balls are forced into the gun by the loader! It's just that different loaders use different methods of stopping them crushing the balls - reloaders only feed when they hear a sound, others cut out at a certain force and some have a slipping clutch.