Erik,
My .02 worth on this topic. The G-CODE paddle design is one of the best on the market. As a matter of fact, some leather holster makers have started using the G-CODE paddle on their leather paddle rigs. Retention on the belt is excellent, and it even holds well on pants alone. The design pulls the holster in close to the body, but not so close as to impede a full firing grip.
In comparison to the belt model versus the paddle, I personally prefer the paddle for the ease of removing off the belt. The belt attachments do have a built-in ride height adjustment not found on the paddle. (The paddle requires an add-on attachment called a "mid-low adapter" to lower the paddle height).
My opinions are based on both my personal use and Gunnersalley.com sales of the G-CODE line. From a sales perspective, customer satisfaction/response to the G-CODE line has been outstanding.
Please let us know if you have any more questions regarding the G-CODE line as we'll be glad to try and help.