Anyone out there have both these bags that would care to elaborate?

I was comparing a buddy's Summerlite to my Highlite the other day and my wheels started turning. The full length two-way zip on the Summerlite is appealing to me...as is the draft flap and continuous baffle construction. Seems like for a just few extra ounces, the Summerlite would offer a lot more versatility and a bit extra warmth.