[nilliams]

I compared the output bundles (ran them back through a beautifier for sanity) and it looks like a lot of the benefit comes from the aggressive renaming.

Compare this section of the rollup output:

    return e || (e = new zh({
        enableLongStackTrace: dt()
    })), e.run(function() {
        var r = yh.resolveAndCreate([{
                provide: zh,
                useValue: e
            }], n.injector),
            o = t.create(r),
            l = o.injector.get(th, null);
        if (!l) throw new Error("No ErrorHandler. Is platform module (BrowserModule) included?");
        return o.onDestroy(function() {
            return _t(n._modules, o)
        }), e.onError.subscribe({
            next: function(t) {
                l.handleError(t)
            }
        }), bt(l, function() {
            return o.injector.get(bh).donePromise.then(function() {
                return n._moduleDoBootstrap(o), o
            })
        })
    })

To this from Closure compiler:

    var c;
    c || (c = new Af({
        Lm: yh()
    }));
    return c.run(function() {
        var d = Ne([{
                sb: Af,
                Be: c
            }], a.s),
            e = b.create(d),
            f = e.s.get(ee, null);
        if (!f) throw Error("No ErrorHandler. Is platform module (BrowserModule) included?");
        e.ec(function() {
            return Hh(a.mi, e)
        });
        c.hq.subscribe({
            next: function(a) {
                f.handleError(a)
            }
        });
        return Ch(f, function() {
            return e.s.get(Ze).xp.then(function() {
                Eh(a, e);
                return e
            })
        })
    })

On top of that I did a basic comparison of the number of times the 'function' keyword is present in each bundle:

    $ ag --count function eg-closure.js
    eg-closure.js:2905

    $ ag --count function eg-rollup.js
    eg-rollup.js:4421

Whether this is from inlining or 'better' dead-code removal I can't really tell.

[jessaustin]

...a lot of the benefit comes from the aggressive renaming.

ISTM if we're going to compress the file anyway, renaming would have a much smaller effect on what actually gets served?