Ok, so I've written some code that, for all intents and purposes, should work:

def checkComments(comments):
  for comment in comments:
    print comment.body
    checkComments(comment.replies)

def processSub(sub):
  sub.replace_more_comments(limit=None, threshold=0)
  checkComments(sub.comments)


#login and subreddit init stuff here
subs = mysubreddit.get_hot(limit=50)
for sub in subs:
  processSub(sub)

However, given a submission that has 50 nested replies like so:

root comment
-> 1st reply
   -> 2nd reply
      -> 3rd reply
         ...
           -> 50th reply

The above code only prints:

root comment
1st reply
2nd reply
3rd reply
4th reply
5th reply
6th reply
7th reply
8th reply
9th reply

Any idea how I can get the remaining 41 levels of replies? Or is this a praw limitation?