As posted in another post, personally suspect that almost all American accents/dialects sound twangy to the British ear, just as most British, Australian, New Zealander, and even Irish accents/dialects tend to sound clipped to American ears.
If the British have a glottal stop, you'd have to say the Dutch have a glottal RIP. If you take away the glottal attack and the funny way they spell things, Dutch is quite easy to comprehend.