The major difference is you have to prime your carto the first time you use it. Clearomizer just pour the juice in and your wick should absorb it pretty quickly and you will be vaping away. Priming the carto is not hard and it usually takes me between 5-10 minutes depending on the juice.
The other thing is the glass itself. Clearomizer, lots of them are made of poly so you may have some plastic taste or crack. Get some nice quartz glass or pyrex glass, you won't have that problem.