[Cooker]

I believe that playing Holdem can be a draw back at first, since the hand values are quite inflated in Omaha. You see nut straights, nut flushes, and full houses way more in Omaha than Holdem, and consistently calling with or raising TPTK would make you the biggest sucker at almost every table you sit at. You also see big hands lose often. If a third card to a suit falls in Holdem, your nut straight will often be good. In Omaha, it will usually be beaten. Same for your flush when the river pairs the board. If you do a little study and can make these adjustments quickly (as well as get a sense of starting hand values) then you will do fine coming from holdem.

The mechanics are much the same, so blinds, position, recognizing the nuts, etc will be pretty easy though (although remember AK52 doesn't have a full house on a KKTT3 board since you must play exactly 2 hole cards). This is where learning Omaha will be easiest. In stud you have to deal with an entirely new betting structure (antes and bring ins), position depending on high hand showing, extra betting rounds, remembering dead cards, and the fact that hands can be more concealed (your opponent can make a boat or quads and have no pair showing on his board).

I think your winrate figures to be much better in PLO than limit stud, which is the only version of stud I have played. Therefore, I play much more PLO than I do stud.