EVERYTHING has a level of risk associated with it. There’s nothing that’s 100% fool proof, or 100% predictable, other than death (and there's some that will argue on that one).
5 seconds is as good as anything else. AS calculates the response time prior to the snipe being placed, and if it senses things are running a bit slow, it will pad the lead time. Some users like to use 3 (minimum) seconds, and some users like to use 5, 8 or what ever. Doesn’t really matter. It really comes down to a personal preference.
It’s possible. Instead of there being perhaps a 1 in 10,000 chance that the snipe will be too late, with a shorter lead it might increase to 1.001 in 10,000?
Most of the posts on this forum are from users, and users don’t have much in the way of statistics. My guess is that there are probably a lot of users that specify a 3-second (minimum allowed) lead time, and based on the lack of complaints on the forum about not-in-time snipes, I’d conclude that 3 seconds is just as good as 5 or 10. So, your preference is just as good as the next sniper.
About the only complaint about errors in lead times is when someone specifies 3 seconds and the snipe is placed 6 seconds before the end of the auction. So, if you’re the type that would get upset about this, then use a 6-second lead time.
If another bidder submits a higher bid than yours six days before COB, you're not going to win the item, even if AS submits your bid one second before COB.
The real advantage of AS is that other bidders don't know you're in the game, so the sight of your bid won't tempt them to bid against you. The only value of short lead time is that others don't have enough time to see your bid and react with a higher bid. Seven seconds is usually short enough to prevent competitive bidding.
