What's it like? I've only ever been on Reddit once when someone posted one of my videos and people thought it was me and were accusing of this person being me shilling. It was weird.
Reddit in general: the smaller the sub, the better. The bigger, the more likely it is users will just start shitposting and contributing low effort, low quality content/comments for upvotes. In the big subreddits this also tends to attract thinly-veiled racists and the like (i.e. imagine a 4chan user trying really hard to pretend he's not from /b/ but posting the same stuff).
So, something like the subreddit for videos is awful. On the other hand, a subreddit for physics, or a specific game/anime series, etc. tend to be really good if they have good moderators. The Kill la Kill subreddit was a pretty good example of one that was fun to post in. It's good if you want to discuss something that's very niche with a handful of members, because at least some people on Reddit will find it by accident (for example, my gf moderates a Dir En Grey subreddit with only 100 users).
Problem is with the upvote system is that it can quickly turn into an echo chamber of extremists depending on the nature of the subreddit (the subreddit for conservatives is a good example of this, it's gotten to the point where most of the content reflects extreme fundamental conservative ideals as opposed to moderate conservative opinions, gay hating and the like from what I've heard).