Versions are chained, new features have emerged, design and ergonomics have evolved, but the level of protection has always been particularly effective.
In 8 years of use I've never had to suffer the results of virus attacks or other malicious programs. The detection and neutralization of threats "live" is very fast, the powerful firewall, automatic updates frequent days and thorough analyzes complement the basic arsenal and offers impeccable defense and "silent."
I had the opportunity to test other anti-virus, including Norton happens often in trial version when buying a new PC, and I was often above. Eg Norton had not identified some viruses that have been detected by Bitdefender. I also found the less ergonomic and less configurable system interface.
Among the latest developments, I particularly enjoyed the Safepay browser and keypad that secure the exchange of banking information and reassures the user.
Only downside: Bitdefender's quite greedy in resources and can certainly be a problem on a PC netbook type. However, this aspect has improved over the years and a mid-range PC should have no problems.
In the end this is a great product that represents for me the peace of mind.