Recently completed the build and 6 flights on my new Vectorflight Extra 300 - 66". I installed a Magnum 91 4 stroke and used most of the provided hardware with the exception of the tailwheel assembly and aileron horns.

From a build perspective:

The plane is contructed very well. The cowl and bellypan are clear plastic painted white on the inside. Minor contact on the inside of the cowl removes the paint. I modified the belly pan and glued it onto the bottom of the wing as suggested by Vectorflight . During engine break in I had a fuel leak which caused significant discoloration under the covering where the belly pan was glued to the wing. I corrected this by installing some black trim on either side of the belly pan. The wing design is interesting. It is a foam wing but not sheeted. The covering is very thick - similar to the thickness of electrical tape. The covering provides structural strength. With the Magnum 91 4 stroke, I had to put a fair amount of lead in the nose to get CG at 4 1/8". It also required a small amount of lead on the wing tip to get the lateral balance correct.

From a flight perspective:

The plane flys extremely well. It tracks like an arrow. Th Magnum 91 four stroke with 14 X 6 K Series prop gives decent vertical performance but I would recommend a 1.20 for this plane. It would also limit or eliminate the need for nose weight. The engine is still breaking in so I am still running slightly rich but turning 9,500 RPM. I am planning to convert to a 14 X 6 APC to see if performance improves. The recommended throws seem good with the exception of the rudder. I was unable to hold knife edge with the recommended rudder throws. I increased the rudder throw by about 3/4" and plan to start slowly removing nose weight to improve performance.

All in all, a very nice plane and good value. I would recommend the plane.