From the vids seems 1400 is too slow. 1700 is much easier to hit targets in flight with. Also I think Marcsand2 has said he doesn't like the slower weapons for the same reasons. The thing you can't get around with S2 weapons is the crappy <3k range, which places you at the mercy of anything sniping with larger weapons.
Hey, this nerf on the S4 weapons speeds is new. . .this is a big deal. And what is with this S5 MXOX Laser Gatling with weapon speeds so much higher than anything else we have seen? Can that even be a real thing?
Yes, the faster the projectile speed, the easier to hit, especially in a dynamic dogfight. Although I'm not sure if it's a problem with S2 weapons, as you would anyway use them in a short range. Otherwise, the ship you will be flying is likely to be engaging in close quarters battle.
For example, the default loadout for Super Hornet has 2 M4A laser cannons with approx 2.5km range, and Badger+Bulldog repeaters with 1.5-1.7 km range. I'd say the average effective range against a very agile target (which is the most likely engagement you will be in) is about 300-800m. I've recorded a short video of Pirate Swarm. It may be some noob flying/fighting, but you will see that when I try firing M4As from 2.5 km - it's almost no use, but it's 300-800m when you get the most hits.
The situation changes with a different fight type, map and opponents. If it's not an asteroid field, and your enemy is large, like SH vs Vanguard outside of asteroid field - then I find M4A quite useful at a greater distance. However, at the same time I don't want to go that far away, since I will lose my advantage in maneuverability, allowing me to stay in Vanguard's blind zone. If the target is something like M50, then at 1.5km you can't even see it. The target rectangle is there, but the enemy ship is so small, that you almost can't hit it, except by chance.
So, size 2-3 weapons to me is quite adequate for smaller ships.
This is quite different for a larger ship. When I fly a connie and use 4x M6A with 5.6km range, I can hit small targets like Aurora from that distance, but that's likely because I've got 4 beams traveling towards the centre of my aim mark. But these ships are not very effective at short range, so short range weapons may not work very well. For example I tried 4x Apocalypse Arms Revenant Ballistic Gatlings, and while those have great dps, the range is only 1.5km, so these appeared useless on a connie to me. Long range worked much better. But if I had those 4 Gatlings on a SH, it would be perfect, but overpower.
The MXOX Laser Gatling looks odd. The range and damage per projectile is nothing for a weapon if it's size. But the projectile speed and rate of fire is very high. Although, it may not be very useful anyway, as at <2km this Gatling may not be a very effective weapon, like the Apocalypse Arms Revenant Ballistic Gatling above. If you are using M7A with the same dps and 6.3km range on a larger ship, like a connie (fixed mount), and your opponent is using this Gatling with <2km range, then by the time they can hit you, likely they would be gone, since a ship of this size is hard to miss, and it can't evade very well.
And here is my Super Hornet video. I think it would be very difficult to snipe from large distances in this kind of fight. Also ,even if someone tries, a target like a SH will be so tiny from 2+km range, and anything less SH can close in a matter of 5 seconds, when it's already a dynamic dogfight. You can usually see this scenario at about waive 10+ of Pirate Swarm where Vanguards start to appear. They have big guns and try to snipe you, but as soon as you evade and get close, they are almost defenseless (I don't have this in my video).