I have also found the Neshtan to be a diamond in the rough.
Although Much more of a specific role player than other Minbari Ships: for instance, it excells against Narn (relying on its hull more than Stealth) and agaisnt non-beam oriented fleet (like the Centari).
Although not as much damage potential as 2 Tinashis, it still retains the TL MB's in every arc, and an 8 AD DD P Beam at 30"--agaisnt centari Ion Cannons, that extra point of hull makes a huge difference in survivability.
Additioanly, the Neshtan is not lumbering, and is more manouverable than the Sharlin.
However, I would not take it agaisnt most fighter swarm fleets due to its poor organic fighter compliment. And I will almost always pair it w? Asninta's for this reason.
The Veshtan, in contrast I have never even tried to take feelign that it sacrafices to much from the Tinashi for marginal gains.