outdated cause Lunar never updates anymore
The physical specialization...well, you have more lightning skills that you will be spamming. You would only have 1 physical skill (Spinning Spear Strikes) that will be spammed a lot while True and regular Dragon Leap are mostly just for pushing and some air damage. Flying Dragon, well, it's just powerful for one time, and a friend of mine said maxing was not worth it at all. Could not tell there was damage difference. Points there are a waste.
So, that's 1 physical spammable skill (or 3 if you use the Dragons in air combos) VS 5 lightning spammable skills. Single Slash is there only for the hard knockdown, like for Black Holes in M4.
True Lightning Leap is immensely over powered so having the lightning specialization is worth it. Lightning God (bless) makes it even more powerful. You will be spamming Leaps and Lightning God Strike (other rebirth skill) alot for main damage.