Daz Studio is an application. Genesis 3 is the base frame work from which all products with in the Genesis base makes us of and both is available as a free download. The only time you need a license extension is if you plan to included the “purchased” assets as downloaded in your project however if you make a derivative or a original character, or product, off of the Genesis 3 base it’s your property as to fair use. In a lot of ways Genesis is the same as the Epic base character and you can add more functionality via the purchase of fair use assets in the same way you make purchases from Epic’s marketplace.
Iclone on on the other hand you need to buy 3d Exchange and pay a export license even if you just want to export to say Maya, 3ds Max or blender for the purpose of 2d rendering where with Daz Studio fair use is extended off the shelf for any type of 2d rending requirements but only pay the “interactive” license.
Which to go with though depends on your needs but like all products the fair use rights gets confusing and the first step of making a “informed” decision is to read the EULA as well as understanding the difference in scaled fees, just like making Epic marketplace purchases, so the only real advice between the two would be to read the fine print first
If you search the forums I’ve posted my opinion more than once but as to costs for our project Iclone gets expensive real fast due to hidden costs, like per seat licensing, as compared to our upfront costs using Genesis 3 and the continued improvements on Epic’s end to make Unreal 4 a lot more direct compatible with the custom requirements of Genesis framework.
That’s not to say that there are not issues but in our experience Daz Studio and Genesis is the cheaper solution over the long run if your team also includes the creative art skills and development on Unreal 4 continues to improve cross platform compatibility in the area of fidelity of asset.