they aren't truly BIFL, i don't think they're particularly solid, but AIAIAI make modular over ears - so at least not the full unit needs to be replaced as they age. i use a pair and my only complaint is the bleeding - eg on a train, anyone in the adjacent seats is definitely hearing what you're listening to. could be an issue with just the cups i chose though
they aren't truly BIFL, i don't think they're particularly solid, but AIAIAI make modular over ears - so at least not the full unit needs to be replaced as they age. i use a pair and my only complaint is the bleeding - eg on a train, anyone in the adjacent seats is definitely hearing what you're listening to. could be an issue with just the cups i chose though