The McKinley Village project has a number of serious development issues. To call it infill is somewhat disingenuous as infill typically implies that there are already existing infrastructure improvements (storm drainage, sewer, roads, etc. etc.) The developers propose to tie into the already overburdened CSS that runs through East Sac and that frequently causes flooding in heavy rain events.
The reason that there are neighborhood groups other than those in East Sac involved is because one of the two proposed vehicular access points will be 28th Street (next to the B Street theater) where it crosses the RR tracks on its way to the old dump. That suggests a lot of additional traffic for that portion of midtown. The second access will be a new undercrossing of the RR tracks to access Elvas Avenue. That will breach a secondary flood protection levee. The developers do not want to provide a freeway interchange for obvious reasons. There will NOT be any transit serving this location. All of the units are multi-story single family and have at least two car garages. Many will have three car garages. Of course the developer claims "sustainability" and has included tankless water heaters to demonstrate that. Woo hoo! There will be no multi-family and no single story units for seniors. There will be no useful retail, just a handful of the generally useless "live-work" spaces that developers utilize to demonstrate "mixed use" credentials to the City. Virtually all of the new residents will be driving to East Sac or midtown to get all services, a cup of coffee or a quart of milk.
There are typically about 50 trains a day through the Elvas wye as it is a critical component of UP's western train system. (Note how quickly they repaired that trestle after it burned.) I am surprised that UP is cooperating with the developers as I could see people that paid a half million for their slice of "East Sac" someday expecting to control train traffic hours, like people that complain about air traffic after buying a house near an airport. The developers plan to mitigate by dense planting of conifers. I would not want to raise a family in this bowl of diesel and auto pollution.
The East Sac neighborhood groups are not at this time opposed to the project as it is still being evaluated. Many are suggesting higher densities, perhaps with mid-rise condo structures, freeway access, limited vehicular access to existing neighborhoods, larger buffers between the highway and RR, much more neighborhood retail. There has already been a review and comment session with the Planning Commission and these suggestions were brought up by neighborhood reps.
The project site also includes 10 acres or so for moving the Greek Orthodox Church from its location on McK Park. It will seat 600 and include educational facilities and a 150 person outdoor amphitheater. Pleasant spot for that.

There is a already a development application for the church site. The speculation is that the existing Greek church will be demolished and that there will be a mid-rise condo project built there overlooking the park.
All you need to know is that the behind the scenes players here are AKT Development and Phil Angelides. I don't see this City Council denying those two anything they want. It's the economics that don't make a lot of sense. Why pay a half million for a treeless zero lot line townhouse with no yard and constant noise and pollution when you could get yourself a great place in midtown or East Sac for the same or better price?

IMHO, this is merely a purely suburban project shoehorned into an urban location. I don't see this penciling out in the current real estate market for a long, long time. But I am often wrong.
http://www.mckinleyvillage.net/index.html