I guess it's a personal-preference thing ... I've used this (Pac-a-seat or "steeler's seat") for many hundreds of gigs over ~20 years, and I guess I'm just used to carrying it. Since it is "boxy" in shape, it fits nicely on the Rock'n'Roller cart (as you see in the photos I posted), and I can stack something on top of it easily.
And I've gotten used its modest weight and carrying it. As seen in my photo (a few notes back, in this thread), my Rock'n'Roller cart isn't even all that 'full' of stuff, that is, what I carry to gigs is modest (for solo gigs anyway).

It's a different story when my full band (6 pieces) is playing, but as a full band I only do less than a dozen gigs a year; most of mine are solo/duo/trio, and the Pac a Seat is something I don't mind at all "toting" from home to gig and back etc. The Nano 600 has worked great too, I only need my bigger PA on the occasional very larger or outdoor gig.

-Jim