Yes, and no. Top-heavy can very much be top heavy, compare a Katana or Sportster to a Harley big twin. The big twin is much easier to handle at low speed despite being 150lbs heavier than the other to, both the sporty and kat carry their weight very high. While geometry is certainly huge the higher the CG the easier the bike is to tip side to side. Ever notice that the bike is easier to tip in when you have it loaded to hell or carry a passenger, this almost always causes an increase in rake and trail, so in theory the bike would handle slower. ....Yet it doesn't, getting it off a lean takes more energy, but it falls in easier. Likewise you won't have to lean as much to complete the same arc, when you turn the bike you are balancing gravity (from the center of gravity) against the centripetal force from the cornering arch trying to stand the bike back up. This is because the the higher the CG, the further from the contact patch the CG moves, this means that there is more downward force presented to the chassis with the load carried higher than there would be otherwise. Its all vector sums, and it can certainly get very complicated very quickly.