I have SA, Synapse, and Brain Bag (yikes I have a problem) and I think Synapse might be my favorite but I can't see using it for commuting back and forth to work with a laptop. Maybe I prefer the Synapse because I use it for vacation. The BB is so huge it really makes me not want to use it because it will be much too heavy if full. But if you need that much space then you need that much space. I do love the look of the SA the most. It just seems sleek to me. I had good luck with mine going to/from work when using a TB Brain Cell.
I never tried it but you might have good luck with the SA as a carry on. It can hold a lot and if you pack clothes it won't be very heavy. Plus you can probably still fit it under the seat of a large plane. I've crammed my BB under there before.
I agree with "dichroic" about how the SA shines as a travel bag.
My wife used our first SA as her only bag on a quick business trip (two days, one night) a few months ago.
She had a brain cell for her laptop; a freudian slip for her papers and pens; a snake charmer for cables, chargers, etc; a clear quarter packing cube for her toiletries. And she still had room for a "please don't talk to me" inflight book, her ipod, and of course a change of clothes.
She also raved about how easy it was to get things out while it was under the seat.
But it was her ease at getting through security that sold her completely.
In other news, I have recently taken to using my SA as my day bag, almost in preference to my Synapse, and it all comes down to the freudian slip. That thing is essential!
So, Stacybean, I would suggest: hold on to your SA & slip. I'm beginning to see that the gap between "too much stuff for a Synapse" and "not enough stuff for a Smart Alec" is smaller than I thought -- at least when no laptop is involved.
I have a Synapse, which I love, but sometimes it just wasn't large enough to take to work, especially if I was taking a laptop. So I bought a Brain Bag, which I never used because it was just too huge; I have since sold it. This year I got a Smart Alec for those heavy-carry days, and while I'm not enamored of its structure, it serves its purpose. I can fit my lunch and my purse in, as well as a laptop, for those days I walk to work. And I can see it being useful for short overnight trips as well. I love the water bottle pocket, and both side pockets are capacious, which I find very useful. And I have the Freudian Slip, which is great for folders and papers and my iPad.