29-29.5 mh/s eth mining speed at ~80w power usage.
Significantly lower power usage then the previous generations.
I still have to see if at this speed range the card founds as many shares as expected.
80watt vs 120watt in the RX580 looks interesting. But for the price of one 5500XT you can buy 2 RX580, it's worth thinking about. The choice between them will depend on the cost of electricity (W/$) for a particular miner.
You're confusing the 5500XT with the 5600XT which is less than double the RX580. 5500XT and RX580 are within $20 of each other barring AIB fancy coolers.