And here's Bob, stalwart supporter of Ain't Nothin' Wrong With Corn Sugar.
Corn sugar gets a bad rap.
When used in excess it
can lend a cidery flavor and make the beer detrimentally thin. This is especially noticeable in the "kit-in-a-can" recipes which instruct the brewer to double the malt with dextrose.
Now, I say it
can lend a cidery flavor because the potential is relative to the style being brewed. Let's use a middling example, say, 10% of the grist being dextrose. In Imperial Stout that's not going to impart a damn bit of flavor detectable under the broad spectrum of roasted malts. Same with IPA, just covered up with hops. In Light American Lager, it will probably be noticeable.
There's nothing wrong with sugar. Ask the Belgians. They often use sugars of various types for up to 20% or more of the total gravity contribution. Again, however, those are beers with strong flavor characteristics which may cover the sugar-induced flavors; Belgian yeast is chock full of distinctive flavors.
In an IPA, at proportions that don't exceed 10% of the total gravity contribution, I'd use dextrose. It's cheaper, easier to use, ferments more quickly and has no flavor impact potential.
There. The Other Side.
Bob