Yeah, they're not the cheapest by a long stretch, but if your connection is something you NEED rather than something you just LIKE... Andrews and Arnold are worth the premium.
If you will be losing productivity if there's any outage, you'll probably save the price difference the first time you use their support.
I've had good experiences with Zen too, on their FTTP product. (I'd have used AA, but they didn't offer that specific setup.)