I think that is really ridiculous that they won't let you substitute and are charging an escort fee. That's crazy.
But, I found Mike to be very easy going and willing to take any pictures we wanted. The whole thing lasted only about an hour, but I think there were over 200 pictures. I think the bummer about DPS for Escape weddings is that I think the package doesn't cover any reception you set up later or DP. So, I would talk to DFTW about that coverage, if you want it.
I would say that whether you hire an outside photographer or not, I think you should put together a very specific shot "list" of images and/or backgrounds you like. Certainly, the photographer (whomever you pick) will be creative, but there are shots I wish I had gotten that I just didn't think to ask about.
I also think you can peruse the photographers' work on the DPS site, so look at their styles and pick one you like.
And yes, we got our album and CD the next day. I'm not so sure that's normal though. I've heard that maybe they did that for us because we were considered "foreign" since we were coming from Germany, so there was a rush to save on postage. Maybe that was the deal.
With our MK Photos from January, it took about 10 business days before they were up on the internet to view. They were pretty quick.