And what would you think is the best metric to evaluate the gain/loss? USD or BTC?
For example I have one that gives me 26% gain with USD and 16% gain with BTC.
I'm trying to get used to BTC numbers, but not there yet

The results you get will be proportional to the capital you invest.
5% is worthless if you hold a small capital.
20% of those profits may be enough, requiring patience to trade. Unless you do daily trading consistently earn 5% profit.
I will start trading low amounts more frequently to see how it goes.