hanemcm,
Support has commented about reducing the lead-time to improve the chances of AS being able to determine the outcome of the prior bid group auction. BUT, on the other hand, if AS senses that your lead-time isn’t long enough due to ebay’s response time, which may or may not be an issue at the exact time your auction ends, then AS will pad your lead-time. If it pads it, then using 3 seconds would have little impact.
Gut instinct, and that’s all this is based on, if it were me, I’d picked just one of the auctions and go for it. But, it depends on whether you want to put all your eggs in one basket, or try for a deal. The bid group appears to be better suited for getting a deal, but with such a short amount of time between the auctions, the safer bet would be to bid on just one. Of course, you could always place non-bid group snipes and place one of them real low and one high, and hope that you don’t win both.
At this point, you might be well advised to ask support, assuming someone from support doesn’t come to the forum and make a ruling:
http://support.auctionsniper.com/