My bottle of Sainsbury's Tap Room IPA was deposited by a houseguest (cheers Thomas!) and bears the mark of "Tap Room Brewing Company" of Rochester, New York which sounds immediately makey-uppey. Two seconds' research reveals that this does indeed come from Rochester's North American Breweries megaplant, birthplace of a zillion other American "craft" brands.
It's a big boy at 6.3% ABV and a clear dark orange colour. No qualms about the aroma: all lovely lemon sherbet and orange pith. The hops calm down a bit on tasting. Big sweet malt notes take over so the sharp citrus becomes altogether fluffier mango and mandarin smoothie, with just the merest tang of bitterness on the end. After the initial hit it gets more muted, however, and I was finding it a bit heavy and dull by the half way point.
In summary, it hits all of the places you expect this sort of American IPA to hit, but for me it lacks the finesse of the more established brands: your Sierra Nevadas and your Goose Islands. If it were as cheap and cheerful as the Sainsbury's own-branding suggests I might go for it again, but more likely I reckon I'd trade up to something with a bit more hop action.