We've just finished using our VPS with Tagadab and would really recommend them to anyone looking for a UK based VPS. All support tickets were addressed promptly and our server (Win 2k8, 512MB RAM, 20GB HDD) was always performing and a good speed. When we had a problem with Apache on it, which seemed to limit download speeds to about 20% of what was possible, they helped us fix it, which was found out to be one of the modules.
Their control panel is also very good, with easy to manage VPS, and adding IP addresses was also very easy.
The only reason we moved away is because we decided to go for a dedicated with RackSrv, and hopefully I can be writing the same about them in a few months here.
Our theme was actually based on the Drupal theme http://drupal.org/project/ad_novus although looking at it now it does look similar to tagadab. I may change the blocks on the homepage as they do look quite similar.