First off, let me say that this follow up post in is no way intended to bash dual purpose / 3 slot designs. It's only intended to provide a little more information to those who may be considering cross-draw as a carry method and only reflects my personal experience.
Your mileage may vary......
Hopefully the photo's below will better illustrate my point.
The black holster is a Mernickle dedicated cross-draw & the brown a Simply Rugged dual use pancake style.
The Mernickle is shown with a S&W 632-1 (.327) with 3" bbl and the Simply Rugged with a Ruger SP101 (.327), also with 3" bbl.
As you can see the slots on the dedicated cross-draw holster are in the area of the gun's greatest weight, whereas, when using the 3rd slot option on the dual use holster, most of the guns weight is not supported in the same manner.
Another factor, though not as important, is that the slots on most 3 slot designs are at right angles to each other for use in the strong-side application so the belt has to be kind of bent down slighty when using the 3rd slot for CD. This also has a bearing on how well the belt can support the weight of the gun and is also responsible for some "play", however slight, when drawing or reholstering the gun.
When I was using this, or other 3 slot holsters I have / had in the cross-draw application I found that whenever I bent forward the gun tended to cant out from my body and required some readjustment after standing back upright, which is why I mentioned in a previous post that the 3 slots tend to work better for CD with shorter, lighter weight guns. This tendency to cant out can be reduced by tightening the belt, but, no matter how tight I cinched it up it still had an "unsecure" feeling about it. I'm a firm believer that your belt should be tight anyway, no matter the holster, so when I say, "tightening the belt", I'm talking about sucking it in real good too get to that next belt notch.
I hope this info. helps others decide if a 3 slot, or dedicated CD holster, no matter the maker, is right for their needs.