I agree in principle, although in practice allowing Firefox add-ons to be fully equivalent to other features has been a detriment to security, stability and per

I agree in principle, although in practice allowing Firefox add-ons to be fully equivalent to other features has been a detriment to security, stability and performance Only in an abstract "we might have been able to implement security/performance improvements faster if we wouldn't have had to worry about breaking addons" sense. Any other effects are restricted to those people actually using the addon and don't affect everyone else. A powerful extension interface can also be used to improve performance/stability: while e.g. adblocking certainly doesn't come for free, its cost should be more than offset by not running all that crappy code pulled from ad networks.