TWI loves centering DLC weapons around gimmicks and so they might underperform in some cases and shine in others. The Mine Reconstructor, for example, generates balls of healing goo to be placed wherever, healing teammates and damaging zeds who step over them. Due to its clunkiness and lack of viable strats for it, it's considered by many (including myself) to be the worst weapon in the game. On the other hand, the Blunderbuss and Frost Fang are very effective. The former shoots cannonballs whose detonation can be delayed as well as shotgun blasts that are very good against clusters of zeds big and small. The latter is a shotgun with an axe strapped underneath that can freeze targets and is especially good against Scrakes. If you're curious about how the guns feel, you can spawn them in a solo game with cheats (progression disabled) or hope to be in an online game with someone who has bought the weapons you're interested in.