My 60 Do would lock in harriers provided the wind was 5-10 or less,all the mods and mixing helped some. I did look at the Velox,felt it was too pricy for an unknown. I really wanted the 50cc Velox, but has been sold out for months now. I'll most likely fly what I have for now,reflect on the past later. Any experience with the Seagull Harrier 90?