  We propose a two parameter generalization for the dark energy equation of
state (EOS) $w_X$ for thawing dark energy models which includes PNGB, CPL and
Algebraic thawing models as limiting cases and confront our model with the
latest observational data namely SNe Ia, OHD, CMB, BOSS data. Our analysis
reveals that the phantom type of thawing dark energy is favoured upto $2
\sigma$ confidence level. These results also show that thawing dark energy EOS
is not unique from observational point of view. Though different thawing dark
energy models are not distinguishable from each other from best-fit values
(upto $2\sigma$ C.L.s) of matter density parameter ($\Omega_m^0$) and hubble
parameter ($H_0$) at present epoch, best-fit plots of linear growth of matter
perturbation ($f$) and average deceleration parameter ($q_{\rm av}$); the
difference indeed reflects in best-fit variations of thawing dark energy EOS,
model-independent geometrical diagnostics like the statefinder pair $\{r,s\}$
and $Om3$ parameter. We are thus led to the conclusion that unlike the standard
observables ($\Omega_m^0$, $H_0$, $f$, $q_{\rm av}$), the model-independent
parameters ($r,s,Om3$) and the variations of EOS (in terms of $w_X-w_X'$ plots)
serve as model discriminators for thawing dark energy models.
