Sorry guys, a guy offered me a S9i for the same price of the L3+.

I don't mind if I have to mine btc or ltc, which one is the best solution for the next future?

I would get about the same revenue, just a bit more with the S9i, but I think mining btc will become harder very soon, while mining ltc could be a bit easier.

As I said before, I would like to use this miner for at least 1 year.