I don’t know about any usability dis-/advantages, as this is the only service I have tested. Is duck.com open source? Addy.io is and has an option to self host. And it is not US based. But for most users this might not be important.
I have about 250 aliases and I think I never reacht the 10mb limit. But I also pay for the ultimate subscription so I wouldn’t necessarily notice if I did.
True that could happen. However you can use a shared domain to avoid this. It is one more click to generate a new mail address if you think it is worth eliminating that risk.
I don’t know where you get the 1 reply limit from. Can’t find that on their website and definitely wrong for subscribers.
Definitely not affiliated with them in any way. Just a happy customer and though others might be profiting as well.
Sure you could do that. But I am sure that 99.9% of people that use gmail can’t and won’t.