In its purest dialect, it has some affected English but a lot easier to understand than Geordie. Mine is just the accent. In Somerset, I don't even notice I have it but I suspect that's true of all regional accents, at least that don't use localised words. I've got a good ear and can switch to a couple other accents.
I should point out that the band The Wurzels don't hail from Somerset and their accent is actually Wiltshire.
Oddly, Americans I've met don't have any problems with it.