This quilt is so beautifully hand-pieced with special fabrics, I would probably take the time to hand quilt it 1/4-inch inside each piece. It would take some time, but I'd just work on it in front of the tv every night with a goal of finishing 4 threaded needles a night. You don't have to stop and start inside each hexagon; you can run the needle between layers to move from one hexagon to the next.
I would not want to hand quilt it in any other way because of all the seams a grid or cross-hatch pattern would encounter. For me, it's rather easy to quilt through 3 layers but an absolute bear to quilt through seams. If you have pressed all the seams open, hand quilting through seams wouldn't be as hard, but still wouldn't be as easy as just 3 layers.
If hand quilting, I would be ***very*** careful to choose a batting that is easy to hand quilt through. I used an old-fashioned all-cotton batting for my first (and last!) hand quilted quilt, not knowing that there are much easier batts available. Get a sampler of batts to try; you might be surprised at the differences. Mine, for example, had pieces of seed and the oils in it created a lot of drag on the needle.
From the little research I have done, I know I would not use a needle-punched batt such as Warm and Natural (too hard to push the needle through) or a high-loft polyester batt. I would probably get a sample of Quilter's Dream to try (but not the thinnest one). Have also heard that the Fairfield cotton batt hand quilts easily if you pre-soak it to remove sizing. (Took a class from Roxanne before she died, and that was her favorite batt. She said it was great for machine quilting, but a bear for hand quilting if you didn't do the pre-soak.) If you can afford the cost, silk batting is supposed to be a dream to quilt through! Roxanne said silk batts work great for cotton tops and batting. (Sorry, I have forgotten Roxanne's last name. She was from Hawaii and her daughter has carried on her company with Roxanne product names.....)
If I were to machine quilt this top, I would probably try to do old-timey half circles (forgot what they are called -- clamshells?). The hexagons are already extremely geometric, so straight-line stitching by machine would look pretty harsh to me. I'd want the machine quilting to have a softer look and contrast with the straight lines of the hexagons. This could be achieved with free-motion waves, feathers, flames, etc. but alas, my free motion skills are very lacking. I could do the half-circles with a walking foot, though, so my stitches would be even.
Just my thoughts.......