They’re similar but there are some subtle differences.
Ride height... the IBS is more like the Summer Special (original S/S not SS2) which means that it is a bit higher than the GWH. Holster rake... they’re about the same.
Both the GWH and the IBS use the basic S/S holster body so loop placement is, to a greater or lesser degree, the same. Where you may find a small difference is the position of the leading edge of the front loop on the IBS and the leading edge of the loop on the GWH. This is due in part to the difference in construction of the loops and the way the loops on the IBS are stitched to allow for straddling a belt loop while still insuring that the holster cannot pivot or shift once secured by the belt.
With all that in mind, if there is any noticeable difference when wearing the rig it will likely be the ride height... and some folks familliar with the GWH haven’t even noticed that difference. Never the less, the IBS will be a bit higher.
In the simplest of terms, picture a Summer Special with fixed belt loops and you’ve pretty much got the IBS.
