Meh, as a frequent flier of a Empire Frigate and Federation Fighter and Interceptor I’d vote for a stronger sniper. As noted a fight between two snipers take ages, sure you can often kill a fighter/interceptor in 2-4 shots, but generally they won’t get more than one hit on me, after that I’ll either dodge or get our of line of fire. Not to mention how easy it is to spot a sniper aiming in your direction and where he is.
The guided missile is much worse, much harder to know where they are coming from and even if you know it’s coming and try to get away it’s rare that he won’t be able to follow well enough to still catch you in its enormous blast-radius. And then there is all the friendly fire…
My personal experience is the opposite. If a guided is heading for me and I can’t see it to shoot it down, I’ll 180 around a small meteor or tight corner that they shouldn’t be able to go through. I don’t know where you get it’s easy to spot a sniper, if you’re camped out by an asteroid and don’t start shooting at non engaged fighters, no one will really bug you. When your engaged with other close range fighters you can’t really concentrate on dodging sniper fire.