I think either DEX is good for the simple purpose of exchanging hive-based tokens, but Leo slightly edges Hive-engine because it has lower depositing fee. The Leo DEX also looks prettier and seems more responsive than Hive-engine.
The issue I have with either DEX is this limiting thing where all tokens are paired exclusively with Swap.hive. As much as I get that you're trying to make Swap.hive the base token on the platform, I also think it would make life a lot easier if we could trade in other pairs.
Perhaps it might be too quick to make pairs for every coin, but we could testrun making pairs for the top five traded tokens on the DEX now and then work our way up from there.
Instead of every token being limited to what percentage/fraction of Hive it is, what if we let each represent their intrinsic value? I feel like adding extra trading pairs for each token will be beneficial for them in the long run. What do you think?