I can second the comment from James that they do a good job of locating regions within the U.K and also that their matching capability is useless (they only started matching a year ago but it is not ready for prime time and, yes, the size of their database is small). If you need that level of granularity for U.K. ancestry, the test at LivingDNA can be worthwhile even though it lacks any value in matching.
There is one other advantage to testing at LivingDNA. They use a chip that checks a broader range of locations than chips used elsewhere and by exporting the DNA results and uploading to GEDmatch, MyHeritage, and FTDNA (amongst others), one can find matches there that might not match results from some other test provider.
I have had some decent matches at 23andMe, FTDNA, and MyHeritage, but by far the greatest results have been from Ancestry with their large database and new features such as Common Ancestors and ThruLines (too bad they have no chromosome browser).