it's a full range receiver so i don't know why they told you that. i've had no issues reported back to me about them, again i only use JR receivers so i have no first had experience other then during the installation.
directly from the included instruction manual:
Applications
Full range up to 7-channel aircraft including:
• All types and sizes of glow, gas and electric powered airplanes
• All types and sizes of no-powered gliders
• All types and sizes of glow, gas and electric powered helicopters