I have both.
Others mentioned durability, small company and all that....
For night table lamp, either is a good choice as the G2x starts on low. If that's all it'll be used for, yeah, save the dough for batteries.
Mr. Malkoff designed the MD2 as a combat light. So they come with a pair of primaries.
Also why he chose a practically invincible hi/lo device so when the going gets tough, you can opt for battery life.
But...he knew folks just love, love, love those big fat 18650's so the body is oversized. And he sells real nice 18650's...plus he was thinking ahead....
Some of his products feature an MD2 body with mega bright heads that run off the 18650...the hound dog for example comes as a kit with a battery and charger.
Ok, G2 vs MD2 for the average Joe:
MD2 tail stands. G2 does not.
MD2 has a memory for hi or lo. G2 does not.
MD2 has removable head. G2 does not.
On hi MD2 has a better beam.
On low the MD2 is better suited for low light needs.
MD2 has a pocket clip available.
MD2 is upgradeable.
MD2 comes with a hand signed invoice.
Other features as well, but right now I'm drawing a blank...
The only quibble I have with the MD2 is it's round. No anti-roll features stock. But for a few $ you can add a lanyard ring. I use the low profile Elzetta ($4.95)
Now the G2x is a fine light. The low setting will do most of your lighting needs.
But the Malkoff is a better light, with enough difference in size to carry more comfortably in edc situations.