I'd have to say it has way too much downthrust. The wing could also have too much positive incidence. If you have a meter I'd check it. My Giles is at "0" on the wing with about 1.5 down and 2 right. I'm using different props but wide bladed 18-6 or 8 pitches seem about the best. I have flown with a few 10 pitch props and they don't slow down near as well on landing plus they torque the plane much more especially on the aborted landings.
The Giles has ony had a few reported problems, a few broke the wing (I cracked mine) but more than anything I've heard of thrust problems. There must be some kind of assembly inconsistancy because I have heard of wide ranges of up/down and right/left conditions. Mine was really pretty decent out of the box, I had to add 1/2 deg down and 1/2 deg right. I could use a bit more right with some props I've tried (10's mostly).
It's really a good plane but it does have a narrow speed range while landing. Too fast and it won't come down. Too slow and it'll snap in a hurry.
Good Luck,,,
basmntdweller