Even if you are into the competitive side of it, the IWB holster may not be as big of an issue as some make it out to be.

From my IWB holster, I can usually get out of the holster and first shot on target in 1.5-2 seconds.  A typical match at my local club has 6 stages.  Now if an OWB holster cuts my draw time in half, and I'm not sure it will, then I am saving at most 6 seconds in a match.  So, until I got to the point that I was losing to the top competitors in my division and class by 6 seconds or less, I wouldn't worry about the holster.

Rich

"They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety."
- Benjamin Franklin

"So this is how liberty dies, with thunderous applause."
- Senator Amidala (Star Wars III: Revenge of the Sith)