On behalf of myself and others who are serious about asking the original question, thanks to those who have provided considered replies.  After more than a month, I have an answer for myself.  For practical reasons, I have decided I will hold off indefinately on any investment in Dawn content for use in DS.  If I were primarily a Poser user, I am sure I would think differently.

If a somone is able to develop high quality tools for converting Dawn content to Genesis (in DS), then I may start to buy Dawn content for that purpose.

I am also witholding funds for spending on G2 for many of the same reasons. 

I simply haven't found the complelling reasons to spend the money on either of these.  Some of the reasons:

 - I already have a lot of money invested in Genesis & V4/M4 clothing content for use on Genesis.  Unless I see compelling evidence that all V4 content (including high heels and long skirts) can be fitted to Dawn -AND- all Dawn content (including high heels and long skirts) can be fitted to Genesis, I have little desire to invest effort/money on Dawn.

 - I already have a lot of money invested in Genesis & V4/M4 pose presets (mainly for use on Genesis).  Unless I see compelling evidence that poses can be re-used (perhaps using an additional tool such as PoseMaster) on Genesis/Dawn, I have little desire to invest effort/money on Dawn.

 - I already have a lot of time/money invested in Genesis morphs.  I do not wish to spend a lot of additional money on the morphs necessary to get the results I am looking for.

Another word about Dawn content.  Up till now, Renderosity has provided a lot of V4 content which DS users could re-fit for use on Genesis (many of us spent a lot of time figuring out how to get good results).  It concerns me that this source of V4 conent may be drying up with the proliferation of Dawn content.  I hope that someone will see fit to develop a good quality tool for transfering Dawn content to Genesis.