I've had some quotes from BT and talk talk and can't decide. Zen looks quite expensive.
I also have a Asus RT-N56U router. Will that still be good to use?
Thanks for any help
Yes, that's a great router.
It's your choice but I'll just highlight the positives of each ISP you mentioned.
BT - Infinity is the biggest, most exciting fibre optic product out there and I'd imagine it feels pretty damn good to be part of it. Also, BT seem to be constantly making Infinity faster.
TalkTalk - You can get second to none support at the official Members Forums http://www.talktalkmembers.com/forums/
and the pricing is fairer than BT's.
Zen - THE best all-round support out of the three but it's expensive and other than the odd occasions when support is needed, it's better to pay less.
Another suggestion from me would be Sky, I currently use them and am deliriously happy with the service I get. http://www.sky.com/shop/broadband-talk/fibre-optic/
for the package specifications. It's £20 a month excluding calls and line rental and it's TRULY unlimited, not traffic management or anything so you can just max it out.
Sky Broadband Unlimited