One thing to remember is that using G+ for photos will limit you to only being able to get photos for a day you're tapping in to the parks. Which I'm guessing many plan to do, but it's good to note for those reading this that might forget that.
The PhotoPass One Week will cover 7 days from the day it's activated without having to go in the parks. I dunno what by the day costs since I have PhotoPass included with my MK and don't see the option.
G+ in advance is $30/day now. So if you need 3 days and aren't getting G+ to use G+, PhotoPass One Week is a better deal
MDE is WDW only. We use the DLR app at
Disneyland (I know it sounds like nitpicking, but it really matters when you consider the function of MDE versus the DLR app; MDE basically is representing you while DLR app is just a tool; this is probably why we can unlink MB+ from DLR accounts and link it to a different account, but WDW can't).
But we did have PhotoPass for race photos starting same year WDW did (2016; first implemented with Star Wars Dark Side 2016 and then all races on both coasts since then) and all the way until the last race weekend November 2017. Last outside vendor for photos at DLR races would have been Star Wars Light Side 2016.
Functions similar to MDE that you have a code to put in with your bib number.