This woman here is doing a technique very similar to what I’ve developed.
as is this one
I’ve heard a lot of people say that this method couldn’t have been used in the middle ages as it isn’t productive enough. It’s too slow and they would have developed something faster. The reason it’s seen as being too slow is that it takes longer to twirl the spindle than let it free-spin. But, faster spinning wouldn’t help here as it takes just as long to evenly draft out a thread as it does to spin it up. Notice how in both videos their hands are both in constant motion. I notice in the first video that the lady is constantly adjusting what she’s drafting and pulling out snarls and lumps etc. Her spinning hand does not slow her drafting hand at all. If anything, it’s the other way around.
I wonder how they prepared their fibre in the 15th century. With many wonderful modern preparations drafting can take no time at all so maybe fibre prep could be a contributing factor to the spinning method that was developed.
15thcenturyspinning 
This is how I spin my wool as well (I now only use the drop spindle for quickly plying yarn) and after letting the hand muscles get used to the movement I became just as efficient as on the drop spindle, even without a distaff. I have an actual french spindle, which is lovely, but I mostly use knitting needles that I carved a spiral grove in at the top. Both work well.
I would agree that fiber prep makes a big difference though. I spin raw alpaca mostly, and having to stop to pick out vegetable matter or thin out a clump of fiber takes away the efficiency a bit. In contrast, well-carded and commercially carded wool (alpaca and sheep) almost drafts itself with the long-draw. I can just keep a constant spin in the hand while pulling slowly away from the source.
For the raw wool it’s about 30 seconds to make an armspan length of yarn, while the well-carded wool is more like 15.
Thanks so much for your coment! It’s interesting to hear from someone who has done both types of spinning. I’ve been working one my wool the past few days and am working to getting to the point where I can draw out an armspan’s worth of wool in one fluid movement.
I started out using knitting needles but now I use these http://shop.pallia.net/index.php/en/product/view/3/4 as I find I don’t like the taper on knitting needles and so I need to thin the shaft down. I’m not too good wirh carving and keep mucking it up! These are more expensive than knitting needles but I much prefer them. I haven’t tried with a spiral groove though but I’ve seen many french spindles with them.
I’ve also seen a few medieval illuminations from france where what I can see of the spindle looks very similar to the more modern antique French spindles so I wonder if they had spiral tips as well.
I’ve invested in some carders and when they arrive I’m going to have a go at carding my wool that arrived yesterday!
Thanks for the link, I didn’t know anyone made a thing like that anymore (at least for online sale).
Given contemporary videos of old ladies hand-spindling in various places around Europe, it seems like there’s usually SOMEthing done to the tip of the spindle that allows the the wool to catch in some way, either the spiral or a hook, or both. I got started in this method using a long crochet hook, which actually works just fine (I personally didn’t like how cold the metal got, so I switched to wooden needles instead).