The apps I use to browse reddit are Alien Blue on my iPod Touch and iPad, and Reddit is Fun on my Galaxy Note. I actually think both of those apps do a really good job of the comment section, so much so that I prefer to browse subs like /r/askreddit on them. What do you feel is their downfall?
I'm going to have to reinstall AB and give it a whirl again to digest it. I was just unsatisfied with the comments section and preferred the browser as it presented more conversation and replies to posts in a view. Mobile forum threading has always seemed obscenely claustrophobic to me and I feel like there has got to be a better way to do it. The small screen size is a tough constraint though. Even desktop panels often struggle inelegantly with right-margin creep in comment trees I use HackerNode as a Hacker News client and I rather like the UI. Still dissatisfied by the comments though.