Fixed Pitch

Advantages:
Lower head speed is more forgiving, and can help reduce damage in a crash.
Parts are generally cheaper.
Less moving parts means less difficulty for new flyers to set-up properly
Normally come in ARF or RTF kits.
Parts readily available.
Blades are cheaper(sometimes)
Has stability not found in CP helis due to coning of rotor blades.

Disadvantages:
Fixed pitch, means no inverted flight.
Affected more by ground effect than CP heli's
Require constant throttle adjustment to hover.
Coning of rotor disk means wind can be troublesome.
Changes in thrust require more time due to heli having to change rotor RPM.


Collective Pitch
Advantages:
Ability to adjust thrust without changing RPM.
Ability to perform inverted flight
Less affected by ground effect
Flat rotor disk means more agility.
Higher head speed provides more gyroscopic stability.
Thrust changes are almost instantaneous due to rotor already being at RPM.

Disadvantages:
Cannot just cut throttle in emergencies. Even if you set it down, head speed maintains same RPM's when in full collective mode.
More expensive parts.
Complicated rotor head, can be difficult to trim correctly.
High head speed results in more damage in a crash.
Blades can be expensive.
Normally require extensive building skills to assemble.


See everyone thinks of things in terms of FP vs CP....but they forget X-rotation heli's. Honestly these X-rotation heli's like the XRB are and should be in a class by themselves.

X-rotation heli's are FP helis that are extremely stable, especially for a beginner. You would not believe how easy these things are until you actually try one. A X-rotation heli vs CP is a totally different ballgame. The two are so VASTLY different, you really cant compare them.

Simple fact of the matter is that you can learn on any type of heli.

X-rotation heli you can learn on with little to no outside assistance from anyone.
FP single rotor heli, you can learn on, but will probably need some outside assistance.
CP single rotor heli, you can learn on, but will definatly need some outside assistance.