  Field strength formulated Yang-Mills theory is confronted with the
traditional formulation in terms of gauge fields. It is shown that both
formulations yield the same semiclassics, in particular the same instanton
physics. However, at the tree level the field strength approach is superior
because it already includes a good deal of of quantum fluctuations of the
standard formulation. These quantum fluctuations break the scale invariance of
classical QCD and give rise to an instanton interaction and this causes the
instantons to condense and form a homogeneous instanton solid. Such the
instanton solids show up in the field strength approach as homogeneous
(constant up to gauge transformations) vacuum solutions. A new class of SU(N)
instantons is presented which are not embeddings of SU(N-1) instantons but have
non-trivial SU(N) color structure and carry winding number $n=N(N^{2}-1)/6$.
These instantons generate (after condensation) the lowest action solutions of
the field strength approach. The statistical weight (entropy) of different
homogeneous solutions for SU(3) is numerically estimated by Parisi's stochastic
quantization method. Finally, we compare instanton induced quark condensation
with the condensation of quarks in the homogeneous field strength solutions.
Our investigations show that the homogeneous vacuum of the field strength
approach simulates in an efficient way a condensate of instantons.
