OLD PEKAR: Here's an old Harvey Pekar review of Mason & Dixon by Thomas Pynchon. His reaction to Pynchon reminds me of mine to Don DeLillo's White Noise, who also throws in a lot of useless trade names in his books (or he did in White Noise, at least. I have a copy of Underworld I haven't started yet.) Here's Pekar:

The way Pynchon jams information into his books doesn't have much purpose, other than to attempt to dazzle readers. Joyce, on the other hand, uses his immense knowledge far more subtly in the process of creating symbols. Merely citing a bunch of product names like Stacey Adams shoes and Count Chocula, as Pynchon does, isn't a great feat, nor is his giving cutesy names to people and places like Benny Profane and the Bohdi Dharma Pizza Parlor. Anyone can just sit around for 10 years and read, like Pynchon; his reclusiveness has aided in building his reputation, and then write a novel filled with the factual information picked up.

There's a Pekar article collection at the Austin Chronicle too.