Um, it's not "John," it is Alan Entwistle. No relation to the famous bass player.
And to comment about, "tried and true," Mr. Alan Entwistle is about as tried-and-true as it gets in the same way as Dan Armstrong was when he first started making instruments and pickups, and Seymour Duncan working in London at the Fender Soundhouse before starting his own company.
From the Entwistle Pickups website: "UK guitar designer and pickup guru Alan Entwistle has over 30 years of research and experience of hand making custom pickups. His CV includes heading up Hohner’s UK based Custom Shop where he designed models including the JT60, Blond, Black Widow and Revelation. More recently he has designed guitars for Alden and Tanglewood and his electronic circuit wizardry is being incorporated into selected Burns models."
A further review of the website appears to show good pickups at reasonable prices, especially for the UK. I suggest this same question be posted by the OP on the British bass players' forum, basschat.co.uk , to get more input.