I cook on a trailer that has the sniper, vault and a safe on it. I really like the sniper. It is by far the best offset I have ever cooked on. Alot of space easy to maintain temp and with the insulated firebox pretty fuel efficient. It does have its hot and cold spots like any offset but man does it have alot of cooking space. I love the vault also. I would say the vault is not as fuel efficient as I expected it to be. I get about 5-6 hours on a load of charcoal then have to reload. I don't run a guru so maybe if you were using one it would be different. I don't see anybody getting 10-12 hours on a load of charcoal. I don't care if they are using a guru. That being said I love the vault. Easy to maintain temp, lots of cooking space, extremely well made just like the sniper. More even temp across all cooking grates then the sniper.
I don't think you can go wrong with either one . If you like cooking with an offset and tending more to the fire then get you a sniper. If you want more of a set it and forget it then go with the vault. Both of them turn out excellent product and are very well made smokers. Good luck.
Weber 22.5 WSM (2) UDS, Chargriller Acorn, Pit Barrel Cooker, Pitmaker Vault, Safe and Sniper on Trailer