Hurr durr,
I'm not going to buy an ac router just because your wireless card isn't backwards compatible. It shouldn't be like this and your card shouldn't underperform in 2.4GHz. If that's your best honest suggestion then I have nothing to do but keep using my USB wireless card that cost next to nothing and still outperforms a god damn dual band ac card. That's the solution you should be passing on to your users. It's actually a better answer than "buy a new router".
Seriously.
It's hedious. It doesn't make any sense.
