AS for being a sniper weapon, the regular laser rifle still loses out to the regular sniper rifle. Also firing APDS (Cr12.5/shot), the sniper rifle wold do 3D damage (average 10.5), with AP 14 at a range of 550. That completely ignores standard issue TL 10 combat armor. Has an integrated scope, and the Silent trait (-6 to hear). No energy weapon has the Silent trait - either they don't need it (never said anywhere), or they can't be Silent.
The laser sniper rifle is somewhat better, however. 600 range, 6d+3 damage (24 damage average or 11 against TL 10 combat armor, same as the normal sniper rifle). Doesn't have the Silent trait, however. Cost is much, much greater though. Cr9000 compared to Cr700, and Cr42/shot compared to Cr12.5. Also TL 12, beyond the capability of the setting in question, except in probably limited quantities.
As for zero-G weapons, while I have never really liked the accelerator weapons myself, they can also apparently use APDS ammo. Range is extremely limited (27.5, but see Edit below), but damage comparable to the ACR with AP 9. Cost per shot is Cr10. The laser rifle would deal less damage, but have a much longer range. Unless fighting in open space, this probably isn't an issue however.
So, laser weapons have the advantage of potentially unlimited ammunition (if you allow them to use the base/vehiclepower supply during battle). Over time, they do have effectively unlimited ammunition. As a standard issue weapon, ACRs (And Heavy ACRs) are better. As a sniper weapon, the regular sniper rifle is better. And as a 0-G weapon, as long as range is not an issue, the accelerator rifle is better. One possible advantage of the laser rifle is that, while not the best in any single situation, are the best overall. You have the 2nd best standard issue weapon, the 2nd best sniper weapon, and the 2nd best 0G weapon all in one single package.
Edit: Apparently the accelerator rifle has a range of 250 in the core rulebook, but 25 in Central Supply Catalogue. At least my copies. If that range is used, the range of an accelerator rifle with APDS rounds is 275. Greater than the TL 9 laser rifle, but behind the TL 11 laser rifle.
The laser sniper rifle is somewhat better, however. 600 range, 6d+3 damage (24 damage average or 11 against TL 10 combat armor, same as the normal sniper rifle). Doesn't have the Silent trait, however. Cost is much, much greater though. Cr9000 compared to Cr700, and Cr42/shot compared to Cr12.5. Also TL 12, beyond the capability of the setting in question, except in probably limited quantities.
As for zero-G weapons, while I have never really liked the accelerator weapons myself, they can also apparently use APDS ammo. Range is extremely limited (27.5, but see Edit below), but damage comparable to the ACR with AP 9. Cost per shot is Cr10. The laser rifle would deal less damage, but have a much longer range. Unless fighting in open space, this probably isn't an issue however.
So, laser weapons have the advantage of potentially unlimited ammunition (if you allow them to use the base/vehiclepower supply during battle). Over time, they do have effectively unlimited ammunition. As a standard issue weapon, ACRs (And Heavy ACRs) are better. As a sniper weapon, the regular sniper rifle is better. And as a 0-G weapon, as long as range is not an issue, the accelerator rifle is better. One possible advantage of the laser rifle is that, while not the best in any single situation, are the best overall. You have the 2nd best standard issue weapon, the 2nd best sniper weapon, and the 2nd best 0G weapon all in one single package.
Edit: Apparently the accelerator rifle has a range of 250 in the core rulebook, but 25 in Central Supply Catalogue. At least my copies. If that range is used, the range of an accelerator rifle with APDS rounds is 275. Greater than the TL 9 laser rifle, but behind the TL 11 laser rifle.