I have, it’s not great. Maltsmiths is a brand concocted by Heineken to pretend it’s some small craft brewery. My Untappd tasting notes recall that it “poured flat as a pancake, watery with a hint of malt and hop. £6.80 not well spent” (it was ridiculously overpriced at the bar in London City Airport).
Given the amazing beers being produced weekly by small breweries in the U.K., if you want a good strong IPA you have so many better options than this rubbish.