In doing alittle looking on Wikipedia, I found the following:

E-3 Sentry

USAF/NATO aircraft

General characteristics

Crew: Flight crew: 4

Mission crew: 13-19

Length: 152 ft 11 in (46.61 m)

Wingspan: 145 ft 9 in (44.42 m)

Height: 41 ft 4 in (12.6 m)

Wing area: 3,050 ft² (283.4 m²)

Empty weight: 162,000 lb (73,480 kg)

Loaded weight: 325,000 lb (147,400 kg)

Max takeoff weight: 347,000 lb (156,000 kg)

Powerplant: 4× Pratt and Whitney TF33-PW-100A turbofan, 21,000 lbf (93 kN) each

Performance

Maximum speed: 530 mph (855 km/h)

Range: 4,000 NM (7,400 km) (8 hr)

Service ceiling 29,000 ft (9,000 m)

Royal Air Force/Royal Saudi Air Force/French Air Force aircraft

General characteristics

Crew: Flight crew: 4

Mission crew: 14

Capacity: 35

Length: 152 ft 11 in (46.61 m)

Wingspan: 145 ft 9 in (44.42 m)

Height: 41 ft 4 in (12.6 m)

Wing area: 3,050 ft² (283.4 m²)

Empty weight: 185,000 lb (83,990 kg)

Loaded weight: 335,000 lb (152,090 kg)

Max takeoff weight: 334,000 lb (151,636 kg)

Powerplant: 4× CFM International CFM56 turbofan, 24,000 lbf (107 kN) each

Performance

Never exceed speed: 0.83 mach [630 mph]

Maximum speed: 0.78 mach (955 km/h) [This works out to 592 mph]

Cruise speed: 0.72 mach (eco) [A little less than 550 mph]

Range: 5,000 NM (8,046 km) (10 hr)

Service ceiling 43,000 ft (13,106 m)

Rate of climb: 2000 ft/min (610 m/min)

You'll notice there is about a 14,000 ft difference in Service Ceiling between the NATO/USAF aircraft and the one the Brits etc. use!