From what i have gathered the fantoms are a bit better, more power. Go to http://www.fantomracing.com/
Oh click on the Testimonials link and read them all.

Heres some stats.

Fantom - FR15 Racing Engine
Features:


True ABC construction
Turbo design race ported crank
Knife-edge double bushing connecting rod
New rotary carb design features improved idle screw position and high speed needle
New piston design for better performance
Sleeve locating pin
Includes glow plug and air filter

Specifications:


Exhaust: Side
Carburetor: 6.0mm Rotary
Crank: Threaded
Pull Start: Yes
Horsepower: 1.35hp
RPM (max): 43,300
RPM (typical): 39,500
Bore: 15mm
Stroke: 14mm

O.S. .15 CV-R

Displacement: 0.152 cu in (2.49cc)
Bore: 0.598 in (15.2mm)
Stroke: 0.539 in (13.7mm)
Output: 1.2 ps @ 31,000 rpm
Practical rpm range: 4000-36,000
Weight: 6.88/6.82 oz (195/193.2g)



What does ps mean? Under the output.