I've got one.
I have had 3 in the past as the first two had a problem with down moving from the hood,the 3rd one is okay .
It has to be the warmest cost to warmth bag I have ever used it weighs in at 1700g and packs reasonably small for a 4 season bag.If you use a smaller stuffsack it will go a lot smaller, mine packs down to 28cm X 12cm
It takes a while to loft and when it has lofted it takes some effort to get all the air out for packing.
I am 6'4 and 20 stone(and falling) and there is plenty of room in it for me.
My advice would be to phone the shop and ask them to open one out and inflate a mat as you'll be coming in to try it out for size.