I found it to be fairly accurate for what it's worth. I used it for my IM and it was within a minute or two if we weren't including my restroom break. I also used it for some TT's and found that it was fairly accurate for that too.
In general, I liked it and found it easy to use. I was on a 50% promo rate from being an early adopter, however, after 2-3 years of subscription I opted to stop paying for it. Part of it was accident related and last season was pretty much a wash and couldn't justify the $$ for something I wasn't using. The other part of it was that I had given myself a year to transition from TrainingPeaks to Golden Cheetah. Once I had dropped my TrainingPeaks subscription and was fully into Golden Cheetah it wasn't long until I started learning Aero Lab and also dropped BBS. I still use BBS free version from time to time, but not nearly as much as I used to since I don't find it as valuable for pure TT's.
One thing I did like about the premium version was the file downloads. I found it invaluable being able to load up my IM LOU raceplan on my kickr and ride through that a few times to simulate my ride. Maybe I'm missing some other software but I haven't found a program that lets me ride on a course and customize my CdA so I can virtually ride at my pace instead of a generic pace. So the BBS file was nice because that's essentially what it was. Instead of a gps route, it just prescribed the watts that you'd need to traverse your course. To do this I just ran my race simulation for IM LOU, downloaded the file, and loaded that into Perf Pro Studio as a custom workout. I never was able to make it the course before race day but the BBS file was able to make me feel comfortable with the course. On race day I knew how I had to hold my watts and it was just a matter of putting a picture to all those efforts I had put in on the trainer.
In general, I liked it and found it easy to use. I was on a 50% promo rate from being an early adopter, however, after 2-3 years of subscription I opted to stop paying for it. Part of it was accident related and last season was pretty much a wash and couldn't justify the $$ for something I wasn't using. The other part of it was that I had given myself a year to transition from TrainingPeaks to Golden Cheetah. Once I had dropped my TrainingPeaks subscription and was fully into Golden Cheetah it wasn't long until I started learning Aero Lab and also dropped BBS. I still use BBS free version from time to time, but not nearly as much as I used to since I don't find it as valuable for pure TT's.
One thing I did like about the premium version was the file downloads. I found it invaluable being able to load up my IM LOU raceplan on my kickr and ride through that a few times to simulate my ride. Maybe I'm missing some other software but I haven't found a program that lets me ride on a course and customize my CdA so I can virtually ride at my pace instead of a generic pace. So the BBS file was nice because that's essentially what it was. Instead of a gps route, it just prescribed the watts that you'd need to traverse your course. To do this I just ran my race simulation for IM LOU, downloaded the file, and loaded that into Perf Pro Studio as a custom workout. I never was able to make it the course before race day but the BBS file was able to make me feel comfortable with the course. On race day I knew how I had to hold my watts and it was just a matter of putting a picture to all those efforts I had put in on the trainer.