The Prismatech does more damage in exchange for not inflicting any status effects. The status effect Alchemers tend to be more useful because the status effects are helpful against monsters that aren't weak against elemental damage.

It is important to understand that status effects are separate from damage type. It is easiest to explain with an example. A Cryo Knight is immune to shock and is a member of the Construct monster family. Contructs are weak against elemental damage so a Cryo Knight will take extra damage from a Cryotech Alchemer but it won't get frozen.

No offense or anything but the reason the Hail Driver was recommended was because its Elemental, so are the others. It was also said that its useful against Gun Puppy's which it really isn't all that much. You may as well slaughter them with Fire or interrupt them with Shock. Then there's the part about the Freeze damage which has its own problems springing from the ricochet.

Anyway you have to use whichever status compliments your playstyle the most. If you're really having trouble with a single slow enemy then Hail Driver is probably the best, if you have trouble with large groups of enemies then Storm Driver is probably the best, if you just want to deal as much damage as possible and don't care whats getting hit (I love when the fire spreads off the ricochet) then go with the Magma Driver.

The other 2, Nova Driver and Umbra Driver don't inflict status but are slightly more powerful than the other guns. The Umbra Driver is a Shadow damage gun though so you probably don't want that. If what you meant by "spreading fire" with the Firotech was if the ricochet bullets could cause fire then yes they can. If you meant that closeby enemies can set each other on fire then the answer is no (Fire would be way overpowered). Obviously though the bullets bouncing off of one enemy can hit another closeby enemy and set them on fire.

I don't have a Prismatech either (or know what "proc" is, although I have a stretched idea on it) but since the damage meter isn't too much higher I'd assume the damage from the fire would overpower a Prismatech since the Fire is only weakened against Gremlins and Beasts which the Prismatech wouldn't perform so well against anyway. I also noticed, and this may be coincidental since they both have the same chance of Fire based on the description, but I think once you get to MK II you'll see a lot more burning going on. This is from a single shot alone, not counting the ricochet in. The ricochet rate definitely increases though, I barely ever noticed it (if it ever happened) before getting the MK II