Will 285/40/22 fit a 2006 RRS? and is there much difference to ride quaility to 285/35/22?

yes the 35 profile are like being dragged along the floor on a shovel,just remember it also alters the speed you are going when fitting diff tyre sizes.
going from 275/40r20's to 285/40r22's wen your doing 30mph with 20's you will actually be doin 32.4mph with the 22's
going from 275/40r20's to 285/35r22's you will be doing 31.2mph.

Andy. Gone,,TDV8 arctic frost,black leather,colour coded handles,rear entertainment,sunroof.
1980 Rolls Royce,shadow 2 in white.
Gone 07/57 TDV8 santorino,black leather.chrome handle's/mirror's.
Gone 02/52 FFRR vogue.

Speedo will be wayyyy off with 40 profile without dropping the width a tad.

My 285 35's are 1-2mph over RRS gone
Audi SQ5...Gone Audi Q7 S-Line 240 3.0TDI Gone
Audi A6 Allroad Sport 270 3.0TDI

which rides better? 35 or 40?

Nothing in it

I ran 20" 40's on my D3 and now have 22" 35's on my RRS, and apart from more tramlining on the motorway, the ride is no different.

In fact I took my father out (mr anti 4x4 and the fussiest ride quality passenger alive) in the courtesy FFRR Vouge which was running on 20" alloys, and he said mine was smoother. RRS gone
Audi SQ5...Gone Audi Q7 S-Line 240 3.0TDI Gone
Audi A6 Allroad Sport 270 3.0TDI