Most beer drinkers in the mid-western and western states have more than likely only had Harpoon IPA, which is far from the gold standard for post-Ballantine East Coast IPA. Real post-Ballantine East Coast IPA is almost extinct because the breweries that brewed it went out of business. Most of these breweries never made it past a tri-state area because it was much more difficult to break into the distribution channel during the early days of the craft beer movement than it is today.
Let me give you an example of an East Coast-style IPA that most forum members have more than likely never consumed; namely, the higher gravity version of Oxford Real Ale. This beer was an amazing East Coast IPA that was only available on tap, and sporadically at that. It was brewed by the defunct Oxford Brewing Company (known as the British Brewing Company when Steve Parkes was brewmaster). Anyone who attended NHC 1995 had the opportunity to drink Oxford IPA. Neither of these beers was remotely close to the abomination known as Harpoon IPA. Wild Goose IPA, Sam Middleton's Pale Ale, and Red Feather Pale were first class examples post-Ballantine East Coast IPA and East Coast Pale Ale. I would put these beers up against any beer in their respective classes that is available today.
Brooklyn East IPA is a modern take on early post-Ballantine East Coast IPA. I would not call it a flavorless, sickly sweet brew. Brooklyn East IPA uses the classic British base malt plus wheat and citrus-accented British hop combination that made East Coast IPA an immediate hit.
Style: India Pale Ale
Malts: British Pale Ale Malts from East Anglia
Additions: Contains wheat
Hops: East Kent Golding, Willamette, Northdown, Centennial
Alcohol by Volume: 6.9%
IBUs: 47
Original Gravity: 17° Plato
With an apparent attenuation of 75%, I would not call this beer underattenuated.
A modern and interesting take on East Coast IPA is a beer that Heavy Seas classifies as an Imperial Extra Special Bitter. The beer is called Winter Storm. It's basically the East Coast IPA formula applied to British-style strong bitter, including the British practice of using of chocolate malt for color.
Style: Imperial Extra Special Bitter (ESB)
ABV: 7.5%
IBUs: 50
Availability: October-December
Hops: Warrior, UK Goldings, UK Fuggles, Cascade, Centennial
Malts: 2-row, Crystal, Caramalt, Chocolate Malt