Differences, there are a number:
Size - the original was physically larger than the new one
Fill - the original had more, and was heavier
Straps - the original did NOT have any, the newer one does
Weight - due to the size and fill, the original was heavier
For me, I own and run both depending on the scenario. If it is shooting from a single position, or it involves very little movement, I will use the original. If it involves a lot of positions, with a lot of movement, I will use the new one strapped onto the rifle.
For anyone,
Straps - can be incorporated into the old one, just wrapp them around the inside of the "V", I was doing it before the new one came out.
Fill - per above, the bags can be opened to adjust the fill. Also per above, I took out about 50% of the heavy plastic bead fill and replaced it with light weight foam beads. Both of my bags have plenty of fill for stability, but they also weigh about half of what the original did.
IMHO, you can't go wrong with either one. That being said, if I was only going to run 1, it would be the original. Primary reasoning behind that is the size/depth of the "V" is much bigger on the original and it allows you to get a lower / more stable position when placed over an obstacle.
Best of Luck!
