Rowan, I agree about how a bag can feel confining, depends on the size of bag, cut and size of person too. The compact sleeping bag I use is a bit too constricting and I would definitely get a wider cut next time. Nun's comments pretty much sums up my concerns about a quilt, especially that my campmat is fairly narrow, re arms legs on tent floor and waking up cold. As you say, I tend also to use a bag unzipped if its warm enough.

In the end, one just wants a good nights sleep, so whatever works is the main thing, as getting a good nights sleep is important for the next day and really important if sleeping in a tent day after day and riding each day.