Oh, I should add here that, the 2.0s draw about 40% more current (due to the lower resistance) than the 2.8s and that means about TWICE the wattage/heat as the 2.8s.
In practice, the 2.8s work OK but in low humidity situations, you don't get much vapor exhaled. The 2.0s give you more vapor but can be a bit overpowering at times. Overall, the taste of EJ is the same just stronger with the 2.0s. So, a matter of personal preference.