Played both + Dota 5.54 to present and I would say HoN is good if you like DotA. If you like LoL I suggest you stay with LoL but if you're looking for a more stressful game try HoN. I don't know about LoL but in HoN/DotA games can be decided by lineups alone(unless the people playing are shitty ones.).

About the free trial don't even think about doing that because you won't get into ranked games and the guy's you'll play with are shitty players that always leave. I suggest you borrow an account from a friend to see what ranked games play.