When you flop top set in Omaha, you have a couple of options. If you flopped the nuts, and there was heavy preflop action, try and get as much as possible in on the flop. I actually hate having to do this, because with two cards to come a wrap and a flush draw will come after you. Ideally, if there wasn't a ton of preflop action, you can make a moderate sized bet on the flop, and then if the turn comes safe, bet the pot. Players are less likely to chase with one card to come and dimished pot odds.