I just recently got an 05 Busa and I test rode an 08 1000rr a few months ago. Don't get an 07 they are totally different beast. I can't speak for the newer Gen Busa.
Both are fantastic bikes and choosing one would depend on riding style.
I like to hit the twisties at least once a week but I also use my Busa for a 23 mile round trip ride to and from work along with a trip here and there. I did a 1000 miles on the Busa in 2 days and it was a joy to ride. Comfortable with good wind protection. I was able to comfortably go 170 miles before needing a stretch. The Busa also handles the twisties a lot better then I expected. No chicken stripes left on my tires. It takes a little more effort to lean it but not so much that I get tired after a day in the twisties. The suspension is working great for me as it holds a very tight line. I also hate re-fueling and the tank size is nice. If I don't rev her up to much which I don't need to in the mountains or commuting, I get 40 mph all the way up to 50 mph on long stretches. Revving it up though will yield low 30's. I easily go 150 to 170 miles before re-fueling and thats with plenty of gas left in the tank. 200 miles on a flat road would be very likely.
Although my time was limited on the CBR, I can tell you that it has great suspension, if you want it to lean, think it and it leans. It was without a doubt the most flick-able liter bike I have been on. The power delivery is very smooth and impressive. It's similar to the Busa in that it makes power very quick and it cuts through the air like butter when accelerating.
I've been on GSXR 1000's, the 09 R1, and used to own a FZ1. Of all these I would choose the CBR any day of the week.
If I could have two bikes I would have the CBR and Busa but since I can't right now I'd choose the Busa. This is because I ride to much to sit on a CBR all day although out of the above Liter bikes I've rode it is the most comfortable with the exception of the FZ1. If I was just hitting the twisties and riding my daily ride to and from work I might take the CBR over the Busa. The Busa is just more user friendly for the variety of riding I do though.