Been flying my Tech One Yak (The one from Nitroplanes) quite a lot lately...
I really like it more than most foam profiles. Used it to test my autopilots for the big yak.
Here's the good and the bad on it.
It is very sturdy and more rigid than I had expected.
She flies awesome but felt underpowered on 2 cell, so I tried a 3 cell with no luck. I didn't have the battery recommended, so I had a couple of options.
800mah 2S - Flies great for 10 min but vertical performance is reduced.
180-250mah 2S - Light as a feather and excellent flight for short 3 min flight times.
My setup now - I snagged a spare 10x4.5SF prop from daughter's quad reserves, and it's ballistic now with the 800mah battery. (Motor & ESC does not even get hot)
My CG is a little off I think, but it is a blast and it is rigid enough to do blenders without incident.
One build suggestion though, the guides that hold the long CF rods for elevator and rudder, you can use a Coffee Stirrer and glue that to the guide rather than put the cf rod directly through. They seemed to bind and bend before I did that. Now they're perfect and re-center better than any of my other profile foamies.
It flies really slow and is a ton of fun even in a 1 acre back yard!