GX680 have battery packs for AAs which last for ages. The MkIII backs have easily replaceable batteries whilst MkI and II are soldered in but aren't too difficult to replace. Mine have been replaced and there are plenty on eBay with replaced batteries. There are also 3d printed adapters available for modern batteries so the battery problem isn't an issue really. Yes it's heavy but beautify made and the lenses are incredible.
GX680 have battery packs for AAs which last for ages. The MkIII backs have easily replaceable batteries whilst MkI and II are soldered in but aren't too difficult to replace. Mine have been replaced and there are plenty on eBay with replaced batteries. There are also 3d printed adapters available for modern batteries so the battery problem isn't an issue really. Yes it's heavy but beautify made and the lenses are incredible.