Up to now I've been using Pawel's handlebar bag (bikepack.eu) - large has a capacity of "6-10Litres, weight 280g"
it's a bit narrow and you have to work with force to get tent and sleeping bag etc. in.
Then I've been looking at Alpkit's Dry Bags eg Airlok extra - 35 litres 228g - would cost about £13 - very cheap compared to the above mentioned bag

Am I missing something here ? 35 litres compared to "6-10 lire"

Do any of you use Airlok Extra as handlebar bags ? (with or without a harness ?)

Before any CB's pipe in I meant "6-10 litres" !...

(anybody know what a CB is ? )

I imagine a good 50% of people here use an Airlok on the bars but I reckon hardly anyone uses anything bigger the 13L or maybe 20L at a push in winter. IMO one of the nice things about both the Wildcat Mountain Lion and Alpkit Kanga, is the ability to fit different size dry bags to suit conditions, etc.

I use an airlok 13l with some home made straps and an airlok extra 20l without a harness on my jones bars, but because of the loops I can hook the straps around the bars to keep it away from the forks, head tube and wheel.

I use Alpkit 13l and 20l bags. They are very good. The 20l is bulky when full and it's a challenge to keep it from rubbing on the front wheel of my 29er. 13l is much better really.

Not sure i'd call something 6-10 litres as large, but as Stu says i'd want to limit myself to a 13litre dry bag for most of my riding (personally i use 8 litres for all but cold winter trips). Anything bigger and you'll have too many issues fitting/riding with the thing. I'd be surprised if my max capacity id much more than 25 litres so theres no way i'd be looking at using a 35 litre drybag on the bars.

Then i started i just used one of the airlock bags on the bars with a few straps and it worked fairly well as a cheap starter option. Disadvantages are its a faff to fit and remove the bag from the bars when you are around camp, and if you dont secure it properly it might wear the finish from your headtube.

I use a Wildcat harness and a 20l Alpkit Extra Dual, the one that opens at both ends. I like the extra space this gives as it means I don't have to spend 10 mins wrestling my sleeping bag and mat into it, plus it also takes a down jacket and a few other light n squishy things if needed. The double opening works a treat as you can really balance the load inside rather than having one end compacted and heavier than the other.