As always it depends upon your idea of 'service' and what you consider to be 'good food' and 'attitude'?
For example, I reckon that being left alone for most of the time is good and that any food containing spice or pasta means that I will spend the flight asking for spare bread rolls!! Food that is simple and hot and a reasonable quantity of meat and veg that I can identify is good!
Not to mention that you have not mentioned which cabin you can afford to travel in?
I am biased also, VS has been my first choice in long haul for the 17 years that I have been using them and I would make them my first choice - irrespective of which cabin I was travelling in. (I've done them all on long haul.
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That said - I think that the two are neck and neck and only nit-picking between them. You will aways find someone who has had a bad experience on a carrier and for everyone who says, They Are Great another says, Don't Touch Them.
For money - my guess is that BA will be offering good prices as they are in the middle of an extensive campaign.
Let us know your choice and experience!