Re: NorthPoint Cambridge (The one that was train yards, the big plan.)
The common down the middle is a nice feature. Commons and pocket parks are what "proper" urban neighborhoods should have. Otherwise it probably isn't an actual neighborhood, but rather merely a place to house and employ people while they are figuring out how to go someplace else.
Tall shouldn't automatically mean empty space in between though. Although, I could see it make more sense to go tall with 2 or three buildings and then keep everything else lower.
I won't pretend to be a bias sources vis a vis Cambridge parks - I grew up there, I've been kicked off of so many parks for annoying, if eminently reasonable reasons (didn't have a permit, after dark) and downright idiotic ("you can't play soccer here, this is a baseball field!") that it's hard to take a step back. Anytime some Cantab says "green space", my overwhelming reaction is skepticism. It's hard not to make generalizations, but my personal experience is that people prefer to have green to look at, not actually utilize. I don't think it's a systemic issue, because there are good spots (Winthrop Square, Cambridge Common, couple of pocket parks over in Coast). All fairly old, which is important for another reason:
I'd support a Common, but if you look at the parks that succeed in Cambridge - they're generally surrounded by decent density (as you pointed out). Busses is right, we have no reason to believe anything is going to change with the master plan, but
if it were..., here's what I'd want to see happen: the greatest density directly abutting the park. The most successful parks in Cambridge aren't hidden away from the center of activity, they are the center of activity - as you said. I think it's worth noting those active parks tend to be older and more austere.
The analogy of a hurricane is stuck in my head - a "good" Common (in my biased opinion) in Northpoint sit at the eye of the hurricane, the densest development would sit directly adjacent in ring around the Common, and the smaller builds would peter out to the edge from their - the same way the heaviest winds in a hurricane are concentrated closest to the core.
This induces people to the area, provides a market for retail, which can then interact in a positive with the Common itself. Symbi-fucking-osis. Or is syner-fucking-gy? It's the basis for the good parks, the pocket parks, etc...Use the open space for all it's potential, don't just drop a glorified median in. Sure it's a nice upgrade, but it carries an opportunity cost. Anyways as Busses pointed out: best laid plans of mice and men and all that jazz....we're getting Stuytown-by-the-Expressway.