semogue 830, no comparison, in my opinion! You would have to get the Chubby 1 to find comparable backbone. However, you can't really compare the two as boars usually have the edge on backbone, in general.
The 830 is, possibly, the best boar brush for the money. Good luck.
The 830 has a little more backbone. That's not saying that the Duke 2 doesn't, however. The D2 is so dense but supersoft while still having a good backbone and not being floppy, but still having some give. The 830 is has more backbone and a little more sritch but amazing for hard soaps and facelathering.
You can't go wrong with either, but if I HAD to choose, it would be the Duke 2 just because I tend to like softer feel of it.
These are very different brushes IMO. Both fantastic, but very different. Some people just don't like boar. Between the 2, I'd say likely the 830 has more backbone, but I'd prefer the Duke 2. The SOC vs. the Duke 2 on the other hand.....now I'm having a tough time deciding.
The Duke will perform for decades exactly the same as it did the day you first took it out of the box. A boar will change the way it feels over time. This is the difference between boar and badger hair.
Get the Semogue first as it is inexpensive. It will take about a month of using it every other day before it is broken in and settles down to perform consistently. After that it should be fine for the next few years.
I no longer own any boar brushes but I still have the Duke 2 that I bought as my first high quality badger hair brush if that gives you the answer to your question.
I really, really love my semogue 830. I think I'll really like the duke 2 after reading your comments and others. One thing I also considerd was that if I went with the duke 3, I might as well go with the chubby 1 in best since they are so close in price and size. So...long term I'm planning on getting a chubby 1 or 2. But I really like the 22mm size of my 830 and would like. 22mm in badger. the duke 2 seems like the best choice. one concern: Even though i know the 830 will have a little more backbone, I'm hoping that the 21 mm of the duke 2 will seem close to the 830 in size/feel. Does one mm really make that much difference? I dunno.