The most direct way to measure thrust is to buy a spring scale (some have tried the smaller fishing scales) and try a static pull test. I think static tests yield results slightly higher than experienced in the air, but its a good starting point and is usually the point of comparison anyway.

As for "feel" thrust will most directly affect acceleration. If you are only looking at overall maneuverability, then larger batteries are going to cause higher wingloadings and really change the 3d behavior of the plane.

Clark