I'm waiting, even if they are equal or navi is worse for mining waiting will allow you to save some $$$ as a new burst of radeon used 7s go on the market and retailers/distributors start discounting their current inventory. At this point there are a lot of navi leaks but tech leaks are about as reliable as a coin flip.
Yeah but you can probably mine more than $100 of crypto in the months it takes for Radeon 7 to drop $100. In fact you can grab the free games and sell it for $35 - $50 usd per card right now. And Navi won't have free games in the beginning, and at best it will be half of Radeon 7's hash rate (8gb gddr6) and similar efficiency.
Still, only $1.3 profit per radeon 7 per day now.