However a lot of reviews have said that the TalkTalk essentials package is limited to 14 Mpbs
All ADSL2+ products, which LLU is, are up to 24 Meg. However ASA advertising rules require ISPs to only quote speeds which at least 10% of users can attain, so you often will see "up to 14 or 16 Meg" advertised.
1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 20 Meg WBC