Pro's and Con's for a T-Tail

[Plastic Bonsai]

Additional advantages:

Mounting the tailplane high puts it in an area of low downwash gradient making the tailplane a more effective stabiliser and a more aft cg is possible. This also leads to the tail generally having a more positive loading and thereby reducing trim drag

The T-tail raises the tailplane out of the fuselage drag-hole which can reduce your tailplane effective aspect ratio by 20% or more.

Disadvantages:

Very messy loading and structural design.
Tailplane more difficult to clear snow off and access for maintenance and checking.
Tilting of the principle axes of inertia giving rise to coupling issues in roll.