One problem with 1a is that there might be some crew stuff / safety briefing stuff in the overhead bin.
There’s still plenty space further up though.
Even with people in the “loft” area, you won’t be bothered but the only toilet in that small cabin is in front of the right hand side row 1K so unless your comfortable walking through the galley, you need to go the long way found.
IMHO that little loft thing is a total waste of space and should have been another toilet.
The small bonus with 1a is a bit of extra leg room and you do sometimes disembark from the front door into Orlando so a little bonus there.
David