Well the only BR sport coat close to the one I linked for J.Crew is
this, which seems to be slightly lighter but also $30 cheaper, unless the lighting in the photos were off. What do you mean fit better though, more slimming, more space, a bit of everything or?
Sorry about taking so long to get back to you on this. So first let me say that suit fit, especially in part of this case, is a matter of preference. How I like a jacket to fit may not be how you like it to fit, might not be how mac likes it to fit.
The Ludlow stuff from J. Crew has been a hit and miss for me on shoulder width, depending on the jacket. I like the seam of the shoulder to hit at a specific point just at the end of the shoulder (it's kind of hard to explain) but some jackets wouldn't give me that fit without the body being way too small. A size up and the shoulder wasn't right. It all depended on how strong the shoulder was on the jacket. It also doesn't help that, like many people, my shoulders aren't perfectly symmetrical. My left shoulder is higher and more square than my right, which leads to my right arm being slightly longer than my left (this is the fun stuff you can learn about yourself when you start to obsess about fit and/or go to a tailor!) I don't have this problem with the modern slim or tailored (never tried any of the Monogram suits) at BR. A size 40R hits my shoulders perfectly, and the rest of the jacket does as well.
So that's that out of the way; here's the preference part. If you look at the dudes modelling Ludlow jackets they all have a triangle of shirt and tie peaking out through the jacket by their belt. It's the way the Ludlow is cut. I have a navy herringbone linen sport coat that I really like by them that does this less, but it's still there. It's also a little shorter in length than the the BR jackets. BR, for some reason, has only a few pics of their suits buttoned, but the ones I have have a more traditional front that doesn't open up so much when buttoned and the length is closer to the traditional "hands down at your side able to cup the button of the jacket" measurement.
So half practical fit and half fit preference I guess. Again, though, all that said J. Crew makes the higher quality suit (half-canvased and all).