I've been with LV a few times on and off in recent years. Last time I left two years back, the renewal was nearly £100 higher, with absolutely zero changes to car, driver, address, etc, etc. When I phoned to query, their answer was basically take it or leave it. The woman I spoke to started her side of the conversation with, and I quote, "we're not prepared to negotiate, so don't ask." Really? Fair enough. Goodbye.
I've been with IAM Surety for two years. Very helpful phone service, based in Belfast. (I'm not, I'm in Cheshire.) If any of you are IAM members and haven't considered them, it's worth a phone call at least. (Though they wouldn't cover my 9-5 when I Hirsched it, that was over 12 years ago and I think they're more amenable these days.)
There are always minor differences between companies on comparison sites - I always give them all a go every year. Courtesy car cost, legal cover, protected NCD, voluntary excess etc. will vary their effect on the final figure as we all (should) know.
One company that's always been consistent is Direct Line. I've always had a good record, clean licence, mainstream cars, very good postcodes and job descriptions, and since at least 1990 they've never offered anything remotely like a competitive premium.