Here's my take on the Street/Truck Avenger series.
Holley took their 3310 750 V/S carb (most popular, I think) and added some of their most popular accessories, came up with a few different cfm ratings. Electric choke, p/v protection, non stick gaskets, externally adj v/d springs etc. Basicly they added about $60 worth of accessories to a $250 carb and some how came up with a $380 carb. Dunno, math doesn't add up to me.
I'm a Holley guy through and through, but have been known to abuse myself occasionally with a Carter/Edelbrock or a Q-jet, but this just reeks of marketing BS to me. Besides, how is this thing supposedly going to be "tuned" right out of the box? I think the money is better spent on a 3310 or any DP or HP if you want real performance.
Looking at your sig, you would have no use for one of these pieces.
To answer your question on comparisons, there is none. Apples to Bananas here, as the carbs are intended for vastly different applications.
Why make them? Lots of people will believe anything they read in Hot Rod etc. Throw a couple to a magazine 'mechanic' or two, have them rave about it, and watch them sell like hotcakes (think about Horsepower TV, costs a mfr @ 10K to get mentioned at the end of the show, you wouldn't believe how much for the installation spotlight deal). People dig the notion of a "true bolt-on" but we all know there is no such animal.
Ahhh, the power of advertising......