Advantages
- Increased safety during grounds ops
- Increased protection from FOD
- Reduced t/r vibration
- Reduced t/r noise
- Reduced power requirement in the cruise
- "Branding" for the manufacturer - even MD pay licence money for the NOTAR fan
Disadvantages
- Higher weight and drag of t/r section
- Higher construction cost
- Higher power requirement for given thrust
- The 'alleged' Fenestron (also Fenstron) stall
- Higher maintenance cost - Additional maintenance time required, i.e 10 blades,10 strap packs, 10 ......................
- It will not "scale"
- The blanketing effect of the vertical stabiliser can be annoying as you are trying to get that tracking shot as described but you soon learn to fly "around" it.
I think the biggest one is the safety issue on the ground.
The later versions are a little more refined and very powerful