You want to play more high cards in the game you describe than in PLO. 9987ss can be big in PLO, but goes down in value in these games. It's harder to control the size of the pot and the number of players, so you are going to need bigger hands.

Top set may not be a big hand in this game, it may just be a draw. Top set is always drawing to a board pair, but it is also drawing to no flush and no straight. Therefore, a) if you flop top set on a rainbow board it is more valuable than a suited board; b) it is better on an uncoordinated board; and c) you must play coordinated hands. If the flop is K92r, and you have KKQJ, you have 4 extra outs that you wouldn't have if you were playing KK73.

Pay attention to the culture of the table. Is the hold 'em round making the omaha round looser? Is the omaha round making the hold 'em round tighter? Knowing this can guide your play. What is considered a big hand in Omaha? Top pair? Top two? Middle set? If the players are jamming with TPTK, you'll have to get in there and jam along with them, or lose your action.

Hope this helps.

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