As a comparison, here are the W222 figures against the W221 and the relevant BMW and Audi models:
All weights to EU1 standard.
Diesels
S 350 BlueTEC (W222)
258hp/1,955kg (132hp/tonne)
6.8 secs (0-100km/h)
S 350 BlueTEC (W221)
258hp/1,995kg (129hp/tonne)
7.1 secs (0-100km/h)
Audi A8 3.0 TDI quattro (D4)
250hp/1,915kg (131hp/tonne)
6.1 secs (0-100km/h)
BMW 730d (F01)
258hp/1,915kg (135hp/tonne)
6.1 secs (0-100km/h)
V8's
S 500 (W222)
455hp/1,995kg (228hp/tonne)
4.8 secs (0-100km/h)
S 500 BlueEFFICIENCY (W221)
435hp/2,010kg (216hp/tonne)
5.0 secs (0-100km/h)
Audi A8 4.0 TFSI quattro (D4)
420hp/1,970kg (213hp/tonne)
4.6 secs (0-100km/h)
BMW 750i (F01)
450hp/2,015kg (223hp/tonne)
4.8 secs (0-100km/h)
Hybrids
S 400 HYBRID (W222)
306hp/1,925kg (159hp/tonne)
6.8 secs (0-100km/h)
S 400 HYBRID (W221)
299hp/1,955kg (153hp/tonne)
7.2 secs (0-100km/h)
Audi A8 Hybrid (D4)
245hp/1,945kg (126hp/tonne)
7.7 secs (0-100km/h)
BMW ActiveHybrid 7 (F01)
354hp/2,045kg (173hp/tonne)
5.7 secs (0-100km/h)