I've been using Orange since June this year and have got the package you mention.
The setup was really easy for the internet. I did have a problem for 3 weeks getting the talk service working but this was resolved. I get 24/7 free landline and Orange calls which is very good and find the quality more than acceptable.
I have just been upgraded to 8mb speed which seems fine. bear in mind that although it's called 'unlimited' there is a 50gb fair usage policy.
Had one connection drop out that i know of which is less thatn I use to get with NTL. The orange livebox lets you connect 6 pcs, 4 wireless and 2 wired. had no problems with that either.
Go for it!