It really depends on your sleeping style. I personally much prefer a quilt without any sort of attachment system. I just roll up in it like I would at home. With the quilt wrapped around me, it's a snug, cozy sleep. If you attach the quilt to the pad then it's not going to wrap tightly around you, which I find less cozy in cold weather. Opinions differ though and you can easily not use the system if you buy a quilt that has it. I haven't checked, but I presume the enLIGHTened quilts have some loops along the edges or something similar so you can attach some cord. If not, I'm sure Tim would add some for you.
Regarding the footbox, if you're using your quilt in quite hot weather then it is nice to be able to upzip the footbox to keep the feet from getting sweaty, but it's not a huge deal. I like using my quilt totally unzipped (aka 'blanket' mode) when it's warm enough to do so, but in mid-temperature conditions it's not a big deal. It's only a key feature if you're using a 20F quilt on 50-60F nights.