My point is that the crit multiplier really does not change much in actual combat unless your basic critchance is already very high. You have to take several measures to boost that critchance if you want the higher critical multipliers on energy weapons to have a noticeable effect. Guns do not require high critchance to be effective (and benefit from it much less than energy weapons).
As far as weapon tier, it's a loose logical construction based on the level that the weapon becomes available. You can find a cowboy repeater as soon as Primm, and merchants/enemies will have them not much after. You won't get a plasma rifle until much later (you'll be getting a laser rifle around the time the cowboy repeater is available). I don't want to get into a huge semantics argument about this. Can't we just agree that plasma rifles are higher level, more valuable, and rarer than cowboy repeaters, making them logically of a higher category or ranking of weaponry?
I have no problems with specing a character to take 10 luck, finesse and use the 1st recon baret. Almost all characters can benefit from this setup. It's not just a crit-build setup.
The problem with the Q-35 is that even if you spec for it perfectly, you'll only get 125 damage 40% of the time. The other 60% of the time, you'll only deal 32 damage. On Average, you'll deal 69 damage to a target with no DT.
However, if the target has 20 DT, you'll only deal an average of 49 damage... but 60% of your attacks will only deal 12 damage, which is pitiful. Basically, you must get "lucky" to do any real damage with the Q-35. Otherwise, each shot is kind of a waste.
Take a weapon like This Machine for example. you'll deal 65 damage with regular ammo all the time. Whether you are lucky or not, you'll always deal 45 damage to a target with 20 DT.
On average, you'll crit 20% of the time, dealing 162.5 on that attack, which is higher than Q-35's critical attack, On average, you'll deal 84.5 damage per shot with this machine. Not only is the average damage much higher than Q-35's average damage, it's more reliable. With the Q-35, it may take 3 or 4 hits to finally score that critical to finally take that enemy down. With This Machine, you'll know in advance that it's only going to take 2 shots every time at most.
Let's not mention that This Machine's bullets fire faster, and is better in VATS by a long shot. If a character had 125 AP, This Machine will get 6 attacks and will critical 1.25 times during that VATS sequence. This Machine will deal a total of 511.875 damage.
Q-35 will only get 5 attacks with 125 AP and will critical an average of 2 times in the VATS sequence. Q-35 will deal a total of 355 damage.
This Machine > Q-35 by a long shot in VATS. It's advantage is even more superior when comparing regular combat, firing from the hip. It's almost twice as good.
If you do the same anolysis and compare Q-35 with a weapon like Brush Gun, the differences are even more striking.
Q-35 is really, really terrible. This is why I think Q-35 is poorly balanced. It really needs major buffs. If you want to use plasma rifles, you are forced to use Multiplas Rifle. It is really far superior.