  We revisit a simple lattice model of aggregation in which masses diffuse and
coalesce upon contact with rate 1 and every nonzero mass chips off a single
unit of mass to a randomly chosen neighbour with rate $w$. The dynamics
conserves the average mass density $\rho$ and in the stationary state the
system undergoes a nonequilibrium phase transition in the $(\rho-w)$ plane
across a critical line $\rho_c(w)$. In this paper, we show analytically that in
arbitrary spatial dimensions, $\rho_c(w) = \sqrt{w+1}-1$ exactly and hence,
remarkably, independent of dimension. We also provide direct and indirect
numerical evidence that strongly suggest that the mean field asymptotic answer
for the single site mass distribution function and the associated critical
exponents are super-universal, i.e., independent of dimension.
