how hard is Mozart Sonata in D KV 284 as a whole sonata

[takanari]

what grade it would be in if it's to be put into a grade exam?  (I know somehow it's feel like a stupid question but I just need to know it since I'm playing it so I wanna know what level I'm right now.) 

Of course, I can say that right now I would only be able to perform this piece only around 60-70% good (or maybe worse ).  so not to say that feel like I'm great or anything on that.

[elenka]

It's the most difficult one together with the sonata in C moll...

[cas70]

This is of intermediate difficulty.  Henle rates it a 6.

[pianowolfi]

It's not easy for sure, but I think the A-minor Sonata, the late D Major and the C-minor Sonata are harder.
I love this sonata, it's not played very often I think, the variations are wonderful!