Military training should be as long as the service determines it should be, not as long as it is convenient for the servicemember. I know that I am not telling you anything you don't know but training for Navy Reserve DCO's is paltry compared to pretty much every single other officer accession program in the US military, with the exception of staff/specialist types, I think increasing the amount of training will only improve things for the Navy.
Another thing that has not been pointed out is that this may actually save the Navy some money, by consolidating two or more officer accession programs into one saving on all the overhead associated with maintaining separate programs.
That has a lot less to do with recruiting and retention for the other services and a lot more to do with Navy policy to provide personnel for GWOT, because Navy leadership wanted us to make a contribution on the ground.
I am not so sure, I have had mixed dealings with DCO's in my reserve career. Most of those I have dealt with have been at the O-4/5 level but the lack of Navy experience is evident with some even at that level. At least by then even those who don't have a strong Navy background are pretty sharp even if they are still neophytes to a lot of Navy stuff. But what I have seen at the lower level has been a bit more mixed, with some awesome folks but others not so much.
Are Navy Reserve DCO's worth it to the Navy? Certainly, for no other reason that they get DCO's for really cheap. But that doesn't mean the Navy could spend a little more to get a better return on its investment.