Remember, with insurance, as with most things, you tend to get what you pay for - and until you have to make a claim, all you get is a piece of paper, so it's only when you really need the insurance that you find out who good or bad it is.
Things to consider:
If the car is stolen and not found, do they start processing the claim straight away and aim to get you a settlement cheque within 5 working days? Or, as some insurers do, is it their policy to wait for four weeks to see if the car is found, before then spending another 2 or 3 weeks processing the claim, and only then paying out?
Courtesy cars - do they provide one free of charge whilst your car is being repaired? Or only if you use their choice of repairer? Is it available if your car is deemed beyond economical to repair? Is it available if your car is stolen and missing? Will it be a class A car (Peugeot 107, Ford Ka, etc) or something the size of car you own?
Changes to your policy - will they charge an admin fee for any changes, (plus of course the change in premium arising from the change in your circumstances). Do they charge for a duplicate certificate if you lose yours?
When you make a claim, is their ethos to make it as painless as possible, as long as they're convinced it's not a fradulent claim? Or, is it their policy to make it as hard as possible to claim, so that some people just give up?
If your car is delcared a total loss, and you are offered the "market value" as a settlement, which value are they offering you? The price you would pay at a dealership for a similar car? The private sale price? The price you could pick up a similar car at an auction? Or the price you would get if you were trading your car in at a dealership (and how on earth are you supposed to buy a car at that price if you're not "in the trade"?)?
All things to consider, and one reason why I myself avoid Lloyds syndicates insurers, as they have no brand name to protect and so have some very hard-nosed, customer-unfriendly practices.