[quote=@NarayanK]
<Snipped quote by Lugubrious>

She would have more mobility options and use more strength in general, I think. She would also have another arm to support her swordsmanship so she becomes a lot stronger! It'll be less of a hassle to detach from herself on the long run, so overall it's a pretty significant boost to her strengths. It's like a whole new body part for her, I guess xD
[/quote]

I would rate this as a medium armory upgrade then, though one pretty darn close to major by the way you describe it.