I like the 2nd. set better. Lots of details and quite well done smoke clouds.
My 2 cts is that explosions are probably the most difficult to recreate in dios. I suppose the only thing more difficult would be rain drops.
Trouble with most recreations of explosions is that:
1. A fire or smoke is "alive" meaning its dynamic and moving so our eyes expect it to move when we view it.
2. Fires are actually translucent and even almost transparent rather than solid. Unlike water which can be translucent or transparent it still has a "solid" like feel to it.
Which means picking the colors, doing the shades and the blending become very difficult not to mention choosing the material. What may look nice in a photo becomes funny looking to the eyes when viewed up close and personal.
A true challenge for any dio maker. Thanks CP for the links.