I think both are great games, and experiences will obviously differ due to preference and the people you end up playing with (luck of the draw for most of us).
I think another aspect is the level you play at.
To expand on that, a serious amateur dota player will be focusing on the current meta, drafting, mechanics, and require heavy reliance on teamwork to make any progress in any competitive setting (AD2L, CEVO etc.). Many casual players don't understand that even amateur players at this level drill with their team very often, and is more similar to a "sport" than a "game".
I'm certain this is the same in the LoL scene, but I can't comment much since I've only played two games due to pressure from my friends. My initial impressions were however, that the games are very similar on the surface, but they start to become vastly different at a higher level of play.