+5 (or is it 6?) for not attaching quilt to pad.
But personal preference based on experience seems the only way to know what's "best" for each individual under different circumstances. No "one size" fits all.
Here's a link to the page at Nunatak's website illustrating both ways of securing the quilt - to the pad vs separate from the pad - and describing the advantages and disadvantages of each method amounts to a battle between more warmth (not attached to pad) and more freedom (if attached to pad):
As for difficulty of "wiggling" into a "laced up" quilt, the photos at the above link show the Nunatak attachment straps to be simpler to secure than a "lace up" style -- with the Nunatak using a snaplock at each of only two points along the body, and the snaplocks located at the edge of the quilt (which is a key feature for convenience in securing and adjusting the straps).
So, with the Nunatak, you just lay the quilt over your body, sit up and reach under your upper thighs to snap the lower strap into its snaplock (pulling the strap as snug as you like after its snapped);
then lay back and reach under your back to bring the mid-level strap to its snaplock (pulling that strap as snug as you like after its snapped); and
finally secure the top corners of the quilt behind your neck with a single snap, and tighten the shock cord in the hem using a cordlock at the center of the top edge.
No squirming, and can easily adjust the straps by loosening or tightening any of the straps at the snaplock point for the strap along the quilt's edge. With that said, I more often do not fasten the straps at all -- just tuck the quilt edges at a few key points along my body, and adjust as needed for warmth during the night
Ultimately, if someone finds that attaching a quilt to the pad would "always" be necessary to keep a quilt in place, aren't there sleeping bags available that make the bottom into a sleeve (rather than fill) so that you can slide in a pad?