I only started using Brio, as a local and regular hardware supplier of ours became a distributor for them.
Ive found the kits work out a bit cheaper, there is a wider range of internal kits that are useful, and a big choice of external kits, although I dont think they are all available in the UK.
The external kits all have non handed components (they are handed but the kit comes with both hands), which has been really helpful a few times when customer change configuration at the last moment.
The height adjustment method is very easy to use.
Weatherfold 4S-100 is the equivalent to the E3. This Brio kit has a 50mm track.
Disadvantages: the drilling templates are cheap plastic and only last a few goes, although they supply them free. The instructions are confusing the first time, but once worked out assembly is quick.
Brio is Australian like Centor, I wouldnt say there is much between them in quality -both are excellent.
Sometimes I use the Tommafold bifold kit, as it has a 38mm track and helps to keep a slimmer head.
