I have always been under the impression single linked and french/double linked (not dr bristols) snaffels are both mild bits, but the french is slightly milder due to the nutcracker action being reduced with 2 links, and the fact a horse with a small mouth wont get a joint sticking into their palet. There also seems to be more 'play' in a french link which the horses seem to prefer, and the two sides work slightly more seperate for finer control.
However, I recently overheard a shop assistant in a horsey store telling a mother/daughter combo the french link was slightly harsher. I casually stopped to evesdrop as I was curious (and needed to look at the bit section anyway ) She said the 2 links made the bit have a harsher action.
Either way I will continue to ride in my french link as Alli deffinatly prefers it over the single link snaffel, but now I'm like, am I wrong? I kinda thought I knew enough about bits to get me by A french link is slightly harsher?