Stankia that cell is a hybrid IMR. It's the next generation upgrade from the NCR18650CH and NCR18650PD. For what you're using it for, the 10a limit won't be an issue. You won't be able to use it to 30w in your set up, but as you said that's not an issue to you. The purple efest v1 was 2100mah, the highest mah 18650 purple efest I ever saw was the one you are currently using the 2500mah. Again capacity increase only increases run time if that capacity is in the useable voltage spectrum of the mod.
Here's an example-
Cell A (this is not a real battery, just using it as an example)- 3100mah, 10a rated, 3.7v. 2300mah are above the 3.2v mark, 800mah are located after the battery drops below 3.2v.
Cell B (see note for A)- 2500mah, 20a rated, 3.7v. 2200mah are above the 3.2 mark, 300mah are located after the battery's voltage drops to 3.2v.
So in a DNA30 based mod Cell A has 2300mah useable capacity, Cell B 2200mah. That's good for a roughly 4.3% use time between charge increase. Cell A also will not allow you to use the mod to it's full extent, while Cell B will.
This doesn't even go into the long term affects. The harder you run a battery (as in the closer you get to it's amp limit or beyond*), the shorter it's life will be. Cell A will be ran closer to it's 10a limit in the DNA30 even at only 15w than Cell B.
Remember quality of cell also comes into play. Batteries from manufacturer or re-wrapper A may not last as long (number of charge wise) or be as high quality as from B and vice versa. Samsung 25r cells for example are only rated by Samsung to last for >250 charges. The Panasonic Hybrid (NCR18650BD) is for >400. Some re-wrappers get the top binned cells, others get the next tier down. So even if you get two of the same core cell 18650 (say Sony VCT4) from two different re-wrappers (say Keeppower and Xtar), doesn't mean they'll perform the same.
*Never go beyond a battery's amp limit, doing so is dangerous and whatever consequences you incur from it are your own fault