What are the exact rails changes again ? I dont remember something really huge, like 5% damage and tracking more ?
Less cpu, -12% pg, -30% cap use, +10% damage, 5s reload time.
Comparing a thrown-together Megathron fit with a Tempest fit, this gives the rail fit 5% more dps than artillery at 15% better tracking and better range coverage. Throwing numbers around is a bit iffy, as there is no "sniper fleet" more as in old times - you need a coherent fleet doctrine, not just "BS with long-range guns". I can see a setup similar to Hellcats for Railthrons, but I haven't really run the numbers on those.
Gallente ships face(d) two main problems. One is related to range changes: Over time, a lot of changes made "short-range engagements" work at longer and longer ranges (nerfing of WCS, T2 warp disruptors, overheat), so the blaster range got out of scale more and more. On the long-range engagements, the probing changes mean that "long-range" is now "well below 150km", which is hurting the range advantage of rails a lot. (Not that it mattered much at that point, the Apocalypse was then the best sniper by far because it had best dps, best tracking at max range...)
The other main problem for Gallente ships is still the armor tanking setup which is simply done so much better by the Amarr ships thanks to Amarr high dps at extremely long range with the "short-range" weapons. Scorch (and other long-range T2 ammo) fixes will hopefully address that.