Be careful how you use that 6MB during the day though!
I like AAISP's CS reputation etc. but unless you only use your ADSL 'off peak' their pricing just doesn't work.
I've just had a play with their Pricing Calculator: http://aa.net.uk/broadband-prices.html
(NB doesn't seem to work with IE8).
Picking 40GB peak (my current peak package + unlimited off-peak) allowance comes out at around £140 per month!
I currently use around 30GB during the day throughout the month - so that comes out at over £100 against the £19.99 I'm currently paying...
So for those that use their connection during the day I can't see how AAISP will work.
In your experience it seems whether you're with Enta or AA you have issues with day time internet