I have over 1000 hours on this game, with 99% of them using guns instead of energy weapons. Sneak doesn't seem to expanded upon, and you are pretty much forced to kill everyone and even when you try to sneak, it is just way to easy for people to get [Caution] or alerted to your presence. Energy weapons seem very weak compared to guns, with guns like pacenia(special hunting rifle), medicine stick, etc. The energy weapons are bad in comparison. It's hard to find ammo for them, and AMR seems better than Gauss because Gauss cripples WAY too much when it should kill. Brush guns, AMR, sequoias, all better than plasma rifles and laser rifles and their pistol counterparts. Need I go on?

Holorifle? Gatling laser?

You find sneak useless? It's really very useful with the right perks.

Energy weapons are supposed to be rare and their ammo as well... But in New Vegas you can recharge energy weapon cells and if you look in the right places you can find more than enough ammo. Places such as fiend territory and the Van Graffs place in Freeside.