I've tried the Heineken recently too & I think there are differences but nothing crazy different like you mentioned. I know the St Pauli is brewed in Germany & the Heineken is brewed in Holland. The Heineken has been the best tasting 0.0% advertised beer I've tried so far.Non-alc St. Pauli, Stella, and Heineken all taste similar to me. They're all very good for non-alc but the Clausthaler is in a different league.
Lagunitas has two VERY good offerings as well - a non-alc IPA called "IPNA" and something that tastes like hopped sparkling water called "Hoppy Refresher". The refresher is strange but good after a hot day.
I've been meaning to buy the Lagunitas... I've seen it at walmart too.