Any modern band that comes close to Mahavishnu Orchestra ?

Nice post, ethiessen1.  I think it should be added that the second group, with Ponty, had none of the original members except John.  With mostly different material and sometimes with strings and horns in tow, it was an entirely different animal IMO.  Great stuff, but for the most part nothing like the first group.
Inna, Mclaughlin's pre-Mahavishnu acoustic release "My Goal's Beyond" is a milestone in realm of modern guitar recordings.  It changed the direction of jazz guitar as much as the original Mahavishnu Orch.  set the stage for all the fusion bands, good and bad, that followed.

Coltrane's influence is clear. John himself said that the two biggest influences for him were Miles Davis and John Coltrane, he also liked Charles Mingus.
I am familiar with all McLaughlin's official releases of that time and couple of bootlegs.
In my perception di Meola has more elegance than fire. McLaughlin has both, Paco de Lucia mostly fire but he was a flamenco guitarist. Some of McLaughlin/de Lucia concerts in the 80s were simply spectacular, di Meola was not needed.
I only listen to Inner Mounting Flame and Visions on a regular basis, along with Miles's Bitches Brew where McLaughlin played quite well already. All other Mahavishnu releases are much weaker, though the composition " Sanctuary" from Birds of Fire album is great and "John's Song" from Trident Sessions is pretty good. " Inner Worlds I&II" from Inner Worlds okay, "Birds of Fire" from Birds of Fire okay too.

This is from his second Shakti group. That mandolin bothers me a little, but John is great. Sound quality is not good.

https://www.youtube.com/watch?v=WVdgNXXbm_k

Not Mahavishnu but almost an orchestra. Quite good, isn't it?

https://www.youtube.com/watch?v=ADwfyxpriAM

Enjoying your thread. Not new, more of a root, but a direction to go if not already a fan. 

https://www.youtube.com/watch?v=8CtbhMMTqjc

Maybe newer Mike Stern, or Allen Holdsworth, but as has been mentioned, Mahavishnu Orchestra was a very unique band, in a unique time. Try some of the Chad Wackerman recordings.