Are you face lathering? Or changed the application style, if bowl lathering?
Which boar? I have 4-5 very different boar brushes and i find i have to spend the most time trying to develop a good lather with my SOC.
Have you changed anything else?
If you're asking me, yes I face lather with all my brushes. Same application style, but I do adjust the lathering time based on the brush. I lather until I'm satisfied with the lather I produce, regardless of the brush used. I've tried at least four different Semogue and Omega boar brushes. I've been shaving with many of these brushes for more than 20 years, so of course I've changed things around in that time. I'm a pretty scientifically minded person, so what I'm talking about is changing only the brush and keeping everything else as constant as possible. Overall, I get my worst shaves with my boar brushes, and my best shaves with the newest synthetics. I can easily tell the difference, but yes, I'd say the differences are still pretty small. Even the shaves I get with my boar brushes are still good, the other brushes just result in a better shave. There's no doubt in my mind at all.