So far, from what I've seen, I really like your Sam.
I'm not entirely caught up on where you've taken him from, but he's still got those same Sam qualities that just make him that loveable floppy puppy. And Drunk!Sammy was just seriously, spot on.
I can honestly say that I'm super interested to see how he develops without Dean right now, because loner Winchesters are interesting! I really do love what you're doing with him so far!