Things have seemed to run a little slower than usual recently, Chemist, but my personal advice is NOT to expect, anticipate, or even desire an outbid notice. The whole point to sniping is NOT to set an incremental bid, like the nibblers do, but to set an absolute maximum, since you only get one chance to bid.
If you are willing to up your snipe, and even more of you are depending on an AS outbid alert to do that, then you are not bidding your max. Decide what you will spend and stick with that one snipe. Even if AS is not running slow, if someone bids late in the auction (not necssarily a sniper, just a late bid), chances are you would not get the message in time. Later on you may regret if you did not bid your max.