I think Infinite Jest is a giant novel only in the most literal sense. Otherwise it's just terrible (though I know you and some other people I respect disagree strongly).
The point is, don't feel sad and alone if you like Wallace's non-fiction and find yourself hating his novels.
I like Infinite Jest the way I like R.E.M.'s "Murmur", in the sense that I can understand how either might fall apart at close inspection, but both are so effective at generating a mood for me that I have no motivation to do that.
I like the way DFW writes, but I'll happily cop to liking his essays more than his nonfiction. And again the short stories are unpleasant; sort of like how Elliott Smith can only seem to write songs that are at bottom about heroin addiction, DFW can only seem to write stories that are about how unhappy he is with the kind of person he is.
Also, DFW has sort of become a nerd literary signifier, a way of saying "once upon a time I put down the Xbox controller and picked up a Great Book". He didn't do anything to solicit that response, so I'm a bit wary about nerds sniping at him, because, hipsterism.
Everyone should go read Master And Margarita first.
The point is, don't feel sad and alone if you like Wallace's non-fiction and find yourself hating his novels.