...I migrated last week. Newnet was on my shortlist, sorry can't comment on ADSL4LESS.
The only reasons I decided against them were
1. They charge a migration fee - Could get this free elsewhere
2. They charge £9.40 to upgrade - I was on 1Mb and wanted 2Mb
3. Any usage over the included 2 Gig is charged in 3 Gig blocks and as I sometimes go over 2 Gig this would cost me an extra £2.70 a month.
These things may not affect you.
I presume you are aware that the £11.95 is if you pay for 12 months at once, otherwise they charge £12.95 per month.
Have you checked out their forum click here
In the end I went for IDNet click here and got free migration, free upgrade, includes 2Gig and I only have to pay £1 if I go over.
Very pleased so far!