I have three Badgers (100LG, 150 & 200-20). Wait, I have FOUR Badgers (2 100LG, 150 and 200-20) and the Omni 4000. I found the Omni different than the Badgers. I'm sure it's just that I'm used to the weight and feel of the Badgers, and that the Omni is a wonderful brush.
One thing I DON'T like about the Omni is that the clip behind the trigger can fall into the body. The 100LG/150 has a "T" on the top that prevents this.
Not a huge issue. I bought the extra 100LG and the Omni at the Garage scale, so paid less than a decent kit costs these days. I was going to keep the "new" 100LG for parts, but ended up putting the fine needle and tip on it.