I have a drop-leg for my G20 and HATE it. My opinion is this is one of the areas hunter needs don't align with military needs. A solider or MP might need that because they have too much "chandelier-o-gear" on their torsos and nowhere better to put it. But try crawling through sage or dense gambel oak with it on and it just sucks.
I've tried bino-harness mounts and they're good if you want to retain your sidearm when you take your pack off, but the G20 is a big gun, and a full mag of 220gr hard-cast makes it worse. I've tried both the Marsupial Razco holster, the Eberlestock Nosegunner, and some Alaska-something-I-forgot and they were all too floppy for me.
The most comfortable option I've found is a pack mounted hip holster. I went with the Blackhawk Serpa which has a paddle release for positive retention/peace of mind (I know some folks hate those but I love them and I believe with proper training it's a very safe system).
This thing is fairly cheap and has a bunch of mounting options (including a drop leg if you want to try it). There's an in-waist holder, a belt attachment, and an adapter plate for molle. What rounds it out is the quick-disconnect adapter that lets you quickly swap from one to the other.
The adapter is the key for me. It makes it easy to move it to my pants belt while in camp and at night I can just bring the holster section into my tent (I'm a safety nut so I preferred a holstered pistol).
If you do this I do recommend taking a heat gun and bending the Molle piece of the plate to fit the curve of your belt better. They sell a smaller V-shaped version but IMO it's not as good, it's almost too thick and stiff to sit right, and too narrow to not flop a little.
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