Actually Dwight, the 883 will run just under even with our TBA all day long in the 1/4 maybe a tad slower and beat us in the 1/8 mile all the time. It cruises very well at 70 on the highway and rolls on power almost as good as the TBA. So from a practical stance in the area of performance it has as much thump as our bikes. If you just look at numbers the bikes are a dead heat. Look up the 1/4 mile and 1/8 miles times on them. Its all over the web. I ride with a very large group. The 883s run about even with me. I do not keep up well with them off the red lights. You also know I know how to ride a motorcycle. They are not outriding me. They run really well.
In the area of 1200, its a total different class of bike. Nobody is handling the 1200s with the TBA in performance.
So if you like the look and the performance is a match then its down to ride. There are a lot of folks that like the thin bike with bent elbows and knees. They sell a whole lot of sportsters. Personally I would opt for the cooler TBA. But not for performance. I don't think you are correct on that. They crank up differently and take getting used to. They are not slow by any means when compared to our bikes.
If you get off the XR1200 and get back on a TBA you will feel like you are on a moped.
But, my garage has a TBA in it not an 883. They do nothing for me in the appearance department. + I am not looking for another light weight cruiser. The poster is and he seems to like the style of the 883L.
I think he should also look at the 1300 Honda Stateline and the 900 Kawasaki if they still make it. Both very well behaved and affordable bikes.