Adding numbers for perspective
GAUSS RATE OF FIRE
30cm, Corvette: 2.4s reload, 25 rpm
60cm, Frigate: 4.8s reload, 12.5 rpm
90cm, Destroyer: 7.2s reload, 8.3 rpm
120cm, Cruiser: 9.6s reload, 6.25 rpm
150cm, Intermediate: 12s reload, 5 rpm
180cm, Battlecruiser: 14.4s reload, 4.1 rpm
210cm, Battleship: 16.8s reload, 3.5 rpm
240cm, Dreadnought: 19.2s reload, 3.1 rpm
RAILGUN RATE OF FIRE
30cm, Corvette: 3.6s reload, 16.6 rpm
60cm, Frigate: 7.2s reload, 8.3 rpm
90cm, Destroyer: 10.8s reload, 5.5 rpm
120cm, Cruiser: 14.4s reload, 4.1 rpm
150cm, Intermediate: 18s reload, 3.3 rpm
180cm, Battlecruiser: 21.6s reload, 2.7 rpm
210cm, Battleship: 25.2s reload, 2.3 rpm
240cm, Dreadnought: 28.8s reload, 2 rpm
[Will edit with more information shortly, my opinion will be bellow this line]
Also ends up with some awkward moments with ROF not accounting warhead as part of weapon cost, meaning either warhead should directly relate to CM, such that subcost is removed, and payload is based off size. Or that ROF should include warhead as something to slow down ROF. Example below.
Prism Class
70cm 1 ton Gauss, 5.6s reload, 10.71 rpm, 10.71 tons per min.
20cm 3.5 ton Gauss, 1.6s reload, 37.5 rpm, 131.25 tons per min.
100cm 6.5 ton Gauss, 8s reload, 7.5 rpm, 48.75 tons per min.
End Result: Making larger gauss weapons is completely worthless now, maximizing ROF with warhead is only recourse.
-Edit-
Minor Rant in Spoiler
Personally I do not enjoy the way this works as is, it creates a situation where we have a Linear drop in fire rate, but a quadratic increase in effective damage. In the case of Capital ship guns, the differences are so small in rate of fire that its almost irrelevant, especially when you consider the raw punch behind such guns. If a 500cm gun can only fire once a minute, that may sound fine on paper, but in practice that means once a minute you are causing significant damage to a target; However, the largest problem is this gives a significant advantage to making guns as small as possible for raw firerate, or just using nothing but Siege ships for massive turrets. This also presents the problem that PD needs to be made comparable to the fire rate of these systems, meaning either the fire rate has to be dropped significantly for PD usage, or missiles (and strikecraft for that matter) suddenly have to be able to cross vast distances within seconds, lest they be torn to pieces.
Applying hard numbers to rate of fire only results in problems where other things need hard numbers to reflect on this, especially when these numbers mean significantly higher rates of fire then many weapons were previously treated (Which were usually treated in regards to naval weapons, which tended to have about half the fire rate listed or worse). Suddenly throwing in hard numbers like this is also bound to lead to situations where as systems are rebalanced, stepping on the toes of everyone who used any of those systems, especially when you consider that Railguns were adopted by a number of people for the fact they are usually considered 'Average', this situation pushes Gauss towards being the average with railguns being a slow sniper weapon in anything short of capital ship sized weapons.
While I like the idea of having a better perspective for weapons proper capabilities, sometimes we leave these matters abstract specifically to avoid issues with our relative balance/scale. Yes it creates problems where you have 'But how do I know when my ships should of died?' as is the old case between the Arthans and the Ra-noth early on, such cases can normally be dealt with by working it out between players, with moderation when necessary, not by applying hard rules. GC is first and foremost a roleplay, with rules and its systems used to keep people in the same relative 'scale'.