good training and constant practice do not protect you from freak events such as structural failiure, incapacitation by bird strike or mid air collision
I can't say that the foregoing never occur, but I can say that no pilot I know has ever suffered any of those at a severity which made deploying a 'chute something they would consider. A freak accident could as likely result from a failure of the 'chute to deploy! I just don't think to protect against these risks, other than the basic cautions of a good look out, and good maintenance.
What's the level of interest in BRS systems? They are STC'd into Cessna 150's, and for probably 6000 to 7000 of these aircraft flying, only three systems were sold. It would appear that the risk vs cost did not work well for everyone else.
I think that being equipped with a BRS would be only one of many factors which would make the Cirrus popular. As Genghis mentions, I understand it was required to make up for other handling deficiencies. It would be those deficiencies which would worry me! I understand that it is a somewhat limited envelope of flight, for which the 'chute can be deployed, what about all the flying you do which is not in that envelope? If the Cirrus had flying characteristics which did not require a BRS, and it was a factory option, I would buy the plane without, given the choice.
These systems are heavy, expensive to buy, and expensive to maintain. You can pay those costs, which are very certainly built into the rental cost of the aircraft, if you want, but know that you are paying a cost which most other pilots consider unnecessary.
I don't intend the foregoing to come across as patronizing, but rather reassuring. You would probably not wear a nomex flight suit for every flight, but I expect that a fire is a greater risk! There are so many "low level" risks in flying, guarding against every one, all the time, gets very heavy and costly.
Your choice though....