Well there isn't much difference between the two from my experience. Usually october glory is a bit more compact, while red sunset spreads a bit quicker. The fall colors are usually similar. October glory may have a bit more leafhopper resistance, but Brandywine probably has the best (and better fall color on most of the trees I've seen in my region). I would personally go with brandywine if I had the option between the whole group, but all are significant improvements over the species IMO.

I can't be of much help other than my books.

Here's what Jacobson, Arthur Lee says and he's opinionated:

Acer rubrum 'October Glory' PP2116 (1961)
Introduced in 1961-62 by Princeton nursery of New Jersey. Leaves with long red stems; stay green longer than usual into autumn, extending the seasonal display, giving dependable late-season crimson-red fall color. Tree rounded, not dense. Female. (Females Produce Seeds which = weeds)

'Red Sunset' Acer rubrum
Originated in the late 1940's by Schmidt nursery of Boring, OR. Introduced in 1966. The most commonly planted Red Maple cultivar in the 1970's and '80's. The name was inspired by the song "Red Sails in the Sunset." Its fall color, at least in the north, is long-lasting and superb orange-red. The tree makes a broadly oval crown. Leaves glossy, thick, strongly three-lobed. Female.

Here are some other interesting sounding ones to me:

'Drake' Acer rubrum: Named after Virgil James Drake of County Line nursery, Hartford, MI. Introduced by Schmidt nursery of Boring, OR. Tree of normal growth rate, its crown fairly natural-looking, not markedly round or pyramidal. But its fall color begins very early and goes through changes lasting a long time: distinctively turning from green to a colored border through shades of blue-violet to red and yellow.

He doesn't list a favorite.

Dax

Jacobson, Arthur Lee ÂNorth American Landscape Trees (1996); Ten Speed Press. ISBN:0898158133

Of the two in the thread title October Glory(R) PP 2116 = 'PNI 0268' is probably better overall. For more details try USPTO web site, plant patent (PP) number search using above number.

Here is a link that might be useful: Arboretum Fact Sheets & Award Winners