Regarding guaranteed bookings, I would say that I have probably tried to use it with Ba on at least 10 occasions, it has worked maybe once. If I have tried it on Lh 10 times, I have been cleared 10 times. It goes deeper however as when one tries to use it with LH, any agent you deal with immediately knows about it and will even suggest it, while at BA the average agent has no idea what you are talking about and it takes them forever to try to implement.
Overall its true that there has been a lot of disappointment among LH Sen's, then again there has also been a lot of disappointment over the years among BA Golds as well....