I generally play a lethality spec for sniper, almost purely PVE.
1. How do you think your Sniper spec is perceived by other classes?
I think lethality is generally considered a good end game PVE and PVP spec. However, I think sniper specs in general are sort of ignored by the general game population. No real negativity towards them, nor any great love.
Mobility is seen as a weakness of all the specs. It's not even that snipers don't want to move, it is just clunky to do so. The slight time delay in standing from cover means all the snipers I've seen eat the red targets in operations boss fights at a much higher rate (Toth & Zorn especially) than other classes.
2. How do you perceive your own spec?
I think it's pretty good for single target damage (PVE operations and PVP) although rather poor for solo questing. I think it's pretty well balanced although a little squishy with a lack of talented defensive abiities.
Oh, and lethality is garbage as a leveling spec.