i use a double needle for free motion quilting from time to time.
for me the biggest consideration is the back, its never going to look like the front - its more like a sloppy zig zag stitch look on the back.
so i save the double needle for quilts when the back look doesn't matter or for when i'm able to just quilt the top with the batting and then i put on a back to cover all the stitch work.
then i do some SITD to attach the backing fabric and then add the binding.
i like using the double needle because you can use different threads in each needle - i've even done it with 2 different variegated threads in each needle.