Hi @dungnan. Welcome to the wonderful world of spinning!
Some people do like Louet wheels more than Ashford and there are people that like Ashford wheels more than Louet. People usually buy what they others around them have.
I didn’t have any spinners around me when I started. My husband bought me an Ashford Traveller as my first wheel on the recommendation of a Master Spinner. With subsequent wheels, I was able to test spin them. I have spun on both Ashford and Louet wheels and far prefer the Ashford wheels over Louet.
The Ashford wheels treadle easier. You have to press much harder on the Louet treadles to get them to move. Because of this and only having a 3-point contact with the ground, they will sometimes rock when you spin.
The Ashford Kiwi has a solid square contact with the ground.
The Louet S17 is only a single treadle wheel. This will only add to the rocking motion when you treadle it. The Ashford Kiwi is a double treadle wheel. Double treadle wheels are much easier to control when you are treadling and spinning.
If it were up to me, it would be the Ashford hands down.
If you were to line up all the Ashford and Louet spinning wheels that people own, the Ashford wheels would far out number the Louet wheels.
Hope this helps you out!