Pros:
Speed - Depending how far you are you could reach 39mbps
No throttling - 99% no issues but have had days when worse than 5mb
No Caps - Currently none but this may change

Cons:
No Setup Instructions - not for average user
Support Hours - Office Hours only for phone, internet tickets 24/7 depending on what you raise
No Email - unlike other ISP's no email service provided
Webspace - non provided but believe a lot of ISP's are phasing this out
Initial Setup Fees - varies depending on package you take but could be looking @ £90 plus cost of cable router if not already got one
Poor Communication - don't keep customers updated or provide relevant feedback most of the time
No Bundles - unlike other ISP's currently they only offer internet access
Faults - Can be costly to customer in regards to diagnosing faults

Overall - If they sorted out their customer support, gave better feedback then they will do well

update: this review is now worthless as the company ceased trading this week