I have both types of the 510 atomizers, I recently got into some juice that gave me trouble in both atomizers, and several of them I've about given up on ever working well again. I decided to chop up one of each and was checking out the differences. Sorry I didn't take pictures my chop job wasn't really pretty anyhow 
Here is just my observations and experience with each of them.
The JOYE 510
The heater coil/cup sits a little higher near the top of the bridge in this model. This seems to make it easier for me to hit the cup with one drop. It has a fire-proof wick that draws liquid from the bottom. I was convinced that it was burning once I pulled it out (gunk check my gallery if u want to see the wick), but really it doesn't burn. I heated it with a lighter for a good while and it simply glowed orange, with only a slight smell that was likely residue burning. Gunk building on the coil can spread down the wick a bit and i think this makes it very hard for the juice to climb back up to the bridge. This led to me getting the atty flooded on occasions, and all i needed to do was blow out the bottom (either blow it out the bottom or more difficultly blow it back up inside.) They worked great at first but as the wick started to get blocked off by gunk, there is no way for the juice to get to the cup. The symptoms of this is having a flooded atty, but also getting the dry atty taste.
That brings me to the shared characteristic of both of the models. The "burning" taste that some people (previously including myself) attributed to the fiber inside the atty, actually comes from the coil itself. Burning both attys they produced a tight heavy plume of vapor I could only describe as toxic. My nose still burns from trying to sniff it to confirm the smell. And I was sniffing it from at least 12" away. Anyhow I only assume it was the gunk burning off but the coil.
The non-JOYE 510
The cup that holds the jucie and coil is actually a little larger on this one, and sits lower in the atty. I believe because of this it has an amazing sweet spot for vapor production. However It is harder to drip onto without chugging liquid down to the bottom. Cart vaping seems to need longer breaks for the juice to get down to the cup. When I vape I like to vape a lot so I usually got impatient and dripped it. With the already larger cup and lower sitting cup, it can become easy to flood by over dripping. Unlike the JOYE this flooding was usually the cup being over filled and so much juice around it, I think it wasn't able to heat any to the boiling point i.e. produce vapor. This was exacerbated by a coil in bad shape due to gunk build up. Another thing to add this one was really really hard to disassemble compared to the JOYE which came out rather easily. The purpose of the "ring" is to direct the flow of liquid into the cup, because if it goes past the cup it will be clogging up the bottom leading to harder drags and eventually needing to blow it out, again this is why you might find dripping with this more difficult.
These are just my impressions after dealing with some of my problems caused by thick juice, but I think the principles apply even if you aren't having any problems. Also when I vape, I like to vape constantly. I might be wrong in some of this, and don't mean to challenge anyone's views. However maybe this will help answer some of the questions I went through reading this thread.
Here is just my observations and experience with each of them.The JOYE 510
The heater coil/cup sits a little higher near the top of the bridge in this model. This seems to make it easier for me to hit the cup with one drop. It has a fire-proof wick that draws liquid from the bottom. I was convinced that it was burning once I pulled it out (gunk check my gallery if u want to see the wick), but really it doesn't burn. I heated it with a lighter for a good while and it simply glowed orange, with only a slight smell that was likely residue burning. Gunk building on the coil can spread down the wick a bit and i think this makes it very hard for the juice to climb back up to the bridge. This led to me getting the atty flooded on occasions, and all i needed to do was blow out the bottom (either blow it out the bottom or more difficultly blow it back up inside.) They worked great at first but as the wick started to get blocked off by gunk, there is no way for the juice to get to the cup. The symptoms of this is having a flooded atty, but also getting the dry atty taste.
That brings me to the shared characteristic of both of the models. The "burning" taste that some people (previously including myself) attributed to the fiber inside the atty, actually comes from the coil itself. Burning both attys they produced a tight heavy plume of vapor I could only describe as toxic. My nose still burns from trying to sniff it to confirm the smell. And I was sniffing it from at least 12" away. Anyhow I only assume it was the gunk burning off but the coil.
The non-JOYE 510
The cup that holds the jucie and coil is actually a little larger on this one, and sits lower in the atty. I believe because of this it has an amazing sweet spot for vapor production. However It is harder to drip onto without chugging liquid down to the bottom. Cart vaping seems to need longer breaks for the juice to get down to the cup. When I vape I like to vape a lot so I usually got impatient and dripped it. With the already larger cup and lower sitting cup, it can become easy to flood by over dripping. Unlike the JOYE this flooding was usually the cup being over filled and so much juice around it, I think it wasn't able to heat any to the boiling point i.e. produce vapor. This was exacerbated by a coil in bad shape due to gunk build up. Another thing to add this one was really really hard to disassemble compared to the JOYE which came out rather easily. The purpose of the "ring" is to direct the flow of liquid into the cup, because if it goes past the cup it will be clogging up the bottom leading to harder drags and eventually needing to blow it out, again this is why you might find dripping with this more difficult.
These are just my impressions after dealing with some of my problems caused by thick juice, but I think the principles apply even if you aren't having any problems. Also when I vape, I like to vape constantly. I might be wrong in some of this, and don't mean to challenge anyone's views. However maybe this will help answer some of the questions I went through reading this thread.
