Bivy bag or 1 Person tent?

I have a bivvy bag (Bask Trekking Bivy) which is brilliant. However not very practical in terms of space to get dressed or something so a small one person tent might be better. I know you can get a single person tent for a few hundred dollars that would be around the 1-2 kg mark.

A bivy bag weighs about 800g and a light weight one man tent weighs about 1.6kg. You get a lot more in a one man tent as you do get some room to move around and cook in. Also the test would give a lot better shelter in wind or stormy conditions. Combining a bivy bag with a small tent fly could be another option.

How about having both. A bivy bag is handy for a late night arrival at tent site, usual Fridays. Quick to get ready and don't have to unload and reload your gear. In particular, you don't carry a wet tent in the morning, your first day of walking. I have been tramping for many years and had two one person tents. My first one is used for car camping. The below link is an image of my second one person tent pitched at Lake McKenzie campsite on Great Walk Fraser Island, Queensland http://member.melbpc.org.au/~dzungn/camp_greatwalk.jpg

click on this link for awesome 1 man tent http://www.completeoutdoors.biz/line/3082/

Once I had an Olympus to share with John Marcussen, and he had a bivvy bag, but not I. I could not keep my bag dry because my polar-plus jacket was covered in snow, and I was jolly cold in my damp bag. So a bivvy bag plus tent is good to keep dry but extra weight. I am wearing shoes in place of boots to make up for it, and staying low, below the snow.

I would rather get a hammock with fly over top