Looks like plasma are running a little over half the power needed for mainstream LEDs. Underdriving LEDS get more efficient quick, so for a slight rolloff on lumens you can get them running close.

Overdriving LEDs does have a debtrimental effect on their durability, with the expected life inversely proportional to the power used. I would be more concerned about what is happening to the power source, except that the lithiums being used were designed to power inefficient incandescents, so they are probably not going to be hurt much.

LEDS actually work better at lower temps, heat dissipation being a consideration.